Make Ahead

Cook's Illustrated's Blondies

July 11, 2021
3.6 Stars
Photo by James Ransom
Author Notes

These are the blondies you'll become known for. A few notes: The key to their flavor is the heavy dose of vanilla -- don't skimp, and don't use artificial extract. Err on the side of under-baking. These are delicious cold from the freezer or fridge (and easiest to slice that way). Adapted slightly from Cook's Illustrated (July 2005).

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Cook's Illustrated's Blondies
  • Prep time 30 minutes
  • Cook time 45 minutes
  • Makes 36
  • 1 cup pecans or walnuts (4 ounces)
  • 1 1/2 cups unbleached all-purpose flour (7 1/2 ounces)
  • 1 teaspoon baking powder
  • 1/2 teaspoon table salt
  • 12 tablespoons unsalted butter ( 1 1/2 sticks), melted and cooled
  • 1 1/2 cups packed light brown sugar (10 1/2 ounces)
  • 2 large eggs, lightly beaten
  • 4 teaspoons vanilla extract
  • 6 ounces white chocolate chips (1 cup) or chopped bar, or 3 ounces each white chocolate and semisweet chocolate chips
In This Recipe
  1. Adjust oven rack to middle position; heat oven to 350° F. Spread nuts on large rimmed baking sheet and bake until deep golden brown, 10 to 15 minutes. Transfer nuts to cutting board to cool; chop coarsely and set aside.
  2. While nuts toast, line a 13 by 9-inch baking pan with foil, leaving enough overhang to help you lift the blondies from the pan when they're done. [Here are Cook's Illustrated's measurements, but you can just wing it: Cut 18-inch length foil and fold lengthwise to 8-inch width. Fit foil into length of 13 by 9-inch baking pan, pushing it into corners and up sides of pan; allow excess to overhang pan edges. Cut 14-inch length foil and fit into width of baking pan in same manner, perpendicular to first sheet (if using extra-wide foil, fold second sheet lengthwise to 12-inch width).] Grease foil-lined pan with butter or oil.
  3. Whisk flour, baking powder, and salt together in medium bowl; set aside.
  4. Whisk melted butter and brown sugar together in medium bowl until combined. Add eggs and vanilla and mix well. Using rubber spatula, fold dry ingredients into egg mixture until just combined; do not overmix. Fold in chocolate and nuts and turn batter into prepared pan, smoothing top with rubber spatula.
  5. Bake until top is shiny, cracked, and light golden brown, 22 to 25 minutes; do not overbake. Cool on wire rack to room temperature. Remove bars from pan by lifting foil overhang and transfer to cutting board. Cut into 2-inch squares and serve.

See what other Food52ers are saying.

  • Ellen Lincoln
    Ellen Lincoln
  • Judith Sensecqua Greenwood
    Judith Sensecqua Greenwood
  • manitouanne
  • Ellen J
    Ellen J
  • Becca Justine
    Becca Justine
Genius Recipes

Recipe by: Genius Recipes

89 Reviews

lvollm November 15, 2021
delicious recipe! the flour weight and cup measures do not agree, which could be part of the reason folks have such mixed experiences. 1.5 cups of flour should equal 6 3/8 ounces (using the King Arthur chart)...7.5 ounces is closer to 1.75 cups flour. i've never had trouble with this recipe bc i bake by weight - would be terrific if the recipe could be clarified or corrected.
Edward G. March 5, 2021
I made the recipe exactly as written and the blondies were amazing, (removed from oven at 23 minutes). I will have to reduce the amount of sugar next time if I want my wife to eat them, but the grandkids and I had no problem finishing them haha. Also, looking at the reviews, there were several people that mentioned the baking time wasn't long enough (22 to 25 minutes), and I have to imagine that they probably don't know how accurate their oven control they believe every oven set to 350 degrees is exactly 350 degrees. No one making these comments said they used an oven thermometer and 'know' their oven temp was 'right on'. I think you shouldn't make a comment about temp until you check your oven. My oven used to measure 335 degrees when set to 350, so I just added 15 degrees....close enough. When it started dropping even more, a repairman repaired it, now it's +/- 3 degrees...don't mess with it anymore.
Noreen F. March 5, 2021
Exactly! I just got a new dual fuel stove and haven’t done much testing yet. Testing in the old gas oven, I discovered that the temp would drop over 50 degrees before the gas kicked on to push it back up. Needless to say, not great for baking.
Ellen L. March 3, 2021
I made these today and they are AMAZING!!! Will definitely make them for years to come!!!
Judith S. January 31, 2021
I’ve made these bars for years, a variation almost identical to Ina Garten’s recipe. I tried these today. I would say stick to Ina Garten! These are underwhelming!
A. R. December 13, 2020
This is my second attempt at a blondie, made very carefully with walnuts and a bit more chocolate and less white chocolate. At 25 minutes VERY undercooked, used a metal pan, parchment paper. I think the altitude (7297') may be to blame, will try it again with high-altitude adjustments - but not sure if I make adjustments for cookies or cakes. For us (boys 9, 12 and myself) these were crazy sweet even with a little less white sugar (another clue that it might be a high-altitude issue)
morgan October 22, 2020
I've been making this for 3 years now, I only use it as a guide and swap in and out ingredients all the time, never had a fail, always delicious and the entire pan finished by the end of the day.
lisa W. July 12, 2020
Made them just as written except about 20g less brown sugar (I would go even a bit less next time making them with white chocolate).I didn't brown the butter but certainly could. I used lovely chopped blond chocolate which gives a bit of depth and a wee bit less sweetness to the blondie. Made for the white chocolate lover in the family. Used pecans. They loved them and even though I am not a big white chocolate fan thought they were very good. Was very careful not to overbake (a bare 23 minutes). They were chewy and not at all dry or conversely underdone. Do need the cooling time to setup.
manitouanne May 8, 2020
Made these, also watched the hilarious recent IG video with the humble Amanda. I burned the pecans and had to toast another cup: quite a sacrifice. I followed the recipe precisely, used a thin metal pan and parchment for 22 minutes. Perfect. Delightful. Well received. A note: burnt butter as an ingredient would make these Burnt Butter Blondies, a variation, also delightful, but not the same thing. Make these! (Also very nice without the chocolate and nuts.)
Ellen J. May 6, 2020
I was a sceptic, too! First, I could tell from the video it was going to be a slimmer profile blondie than my usual go to recipe. This was true, but resulted in an elegant, smooth, delicious blondie! The deep toasted pecans, buttery texture, and vanilla gave it an almost praline type taste, but these were far more satisfying than any praline I’ve ever eaten! The tender crumb and the delightful fragrance were addictive. These are going to be my new go to blondie!
I used only dark chocolate chips (60%). For me, white chocolate would have been too sweet. I didn’t bother lining the pan, but just buttered very generously. It would probably have been slightly easier to get the blondies up with the sling, but it was an at-home quarantine recipe, so we didn’t mind a couple of imperfections. For my oven with no sling and a glass Pyrex, they were perfect at 22 minutes. I think the recipe could be upsized to make a deeper blondie, but it might lose a bit of the velvety texture.
Becca J. February 24, 2020
I'm blown away by the bad reviews for this and I suspect, for the people who are giving bad reviews, that they're doing something very wrong (probably over-baking).

These are my go-to recipe for blondies and they always get rave reviews. The most common thing that happens is people take a bite and immediately say "oh my GOD". I have dubbed them 'crack blondies' because they're so absurdly good.

Not sure where the other reviews are coming from. ¯\_(ツ)_/¯ Your loss!
jessf December 7, 2020
Mfancon February 14, 2020
I made the blondie recipe exactly as written. The directions said to cook 20 to 25 mins. I probably ended up cooking it for the time specified at the top of the recipe because it was not done so I just kept adding on time.
Why there are two different baking times on this recipe I have no idea.
The texture of the blondie is weird, kind of like a muffin. And the taste is just weird too. Any blondie I have ever eaten tasted better then this.
I am very disappointed in food 52 for publishing this recipe.
diane January 2, 2020
I agree with other reviewers that these were WAY underdone. I can’t believe a version of this recipe made it to the Genius Desserts cookbook!! I took them out at about 24 mins and tasted the corner after about 15 mins of cooling. They were basically raw so I put back in the oven for another 15 mins, but to no avail. The edges were edible (albeit very bland), but I had to throw out the entire middle.
Kristin December 29, 2019
I'm not sure these ARE the Cook's Illustrated blondies... or perhaps there have been a few typographical errors. I don't have a CI membership so I can't compare to the exact recipe, but their article mentions browning the butter and replacing some of the brown sugar with corn syrup:
Furthermore, CI themselves recommend artificial vanilla extract, so I'd recommend updating the header notes to remove the snarky admonition against artificial:
Shelley H. December 30, 2019
The recipe explicitly calls for vanilla extract.
It also in no way mentions using corn syrup instead of brown sugar.
I'm not sure where you see those indications.
Luciana December 31, 2019
You're referencing a newer recipe CI has published for blondies. This article is was published in 2014. The more recent CI blondie was published in Dec. 2018. I've been making brown butter blondies for years with extra vanilla and salt so I am glad CI finally figured out the secret to the very best blondies. :) I got the recipe from Allrecipes 12+ yrs ago.
CMS November 24, 2019
These are somewhat bland - and I think too thin, so they dry out.
(Editor: why do you suggest alum foil to line pan but use photo with parchment? )
Try an 8x12 or 9x9 metal pan with parchment paper?
Up the flavor by browning butter and perhaps adding some dried cherries or such to amp chewiness?
Ann June 23, 2019
These were some of the worst Blondies I have ever tasted. Dry, hardly enough batter to fill a 9 x 13 pan, and despite following the recipe exactly, the top never got shiny, or cracked.
I’ll stick to one of the many other Blondie recipes I have collected over the years from church cookbooks and elderly Aunts. They bury this.
CMS November 24, 2019
Pls share an old church recipe!
Ann November 24, 2019
Millie Corbett’s Blondies
Soft butter for the pan
1 1/2 sticks butter, melted
1 3/4 cups light or dark brown
3 eggs, lightly beaten
2 cups flour
2 teaspoons baking powder
Pinch of salt
1 bag (12 oz) semisweet
chocolate chips
Oven at 350, greased 9 x 13
With an electric beater, cream butter and sugar until light. Add the eggs, beating well after each.
Add the flour, baking powder, and salt. Beat only until the flour is well blended. Use a wooden spoon to stir in the chips.
Pour the batter into the pan and use a knife to spread it
evenly. Bake 25 minutes or until golden brown and firm to the touch.
Cool completely on a wire rack. Use a small sharp knife to make 24 bars. Remove them from the pan. The recipe doubles easily, using 2 9 x 13 pans

Hope you enjoy them.
Sigita May 23, 2019
I made these the other day and also found that the were dry quickly despite being wrapped and stored airtight. There were not as chewy as I would like.
Debbie C. May 3, 2019
I love this recipe but they go stale within a day or two. Freeze them if it is going to take longer to eat them. FYI: I ran out of light brown sugar and used dark brown instead. The flavor isn't as good. I first made the original recipe without any changes. I now tweek the recipe to my own preferences. I omit the nuts. I brown the butter and I use a whole 12 ounce bag of Nestle's triple chips (white, milk, semi-sweet).
Marti March 31, 2019
This blonde recipe is great. I browned the butter as others mentioned. I also used 1 cup dark brown sugar plus 1/2 cup coconut palm sugar instead of the light brown sugar. In addition, I used 2oz milk chocolate chips, 2 ounces butterscotch chips, and 2 oz health bar chips. Will definitely make again!

Emma February 26, 2019
These were sooo good. i didn't have any trouble with underdoneness, as others did. Browned the butter, cut the sugar by 25%, and used mostly white whole wheat (what I had). I mixed in pecans and a mix of chocolate chips and chocolate covered sunflower seeds--perfect!!
Gina H. February 7, 2019
Made these on a cold snowy day and they turned out wonderful. I followed the recipe as directed, mostly. At the suggestion of others I browned my butter. I don't like white chocolate so I used a mix of what I had on hand - chocolate chips and heath bar. I also added walnuts. After reading the reviews I was concerned about the cooking time but mine cooked in 25 min. I would wait about 5 min to remove the foil sling to the rack. It takes them at least 30 min to cool and not be gooey. Great consistency.