Chocolate Birthday Sheet Cake With Strawberry Marshmallow Frosting

February  7, 2019
7 Ratings
Photo by Julia Gartland
Author Notes

This birthday cake basically tastes like the best chocolate strawberry Hostess Suzy-Q you ever did have—and I mean that in a good way. The cake is one-bowl and deeply chocolate-y. It is tender and moist and crumbles a bit as you take each bite. And the frosting is fluffy and fruity and light. The lemon juice in the frosting amps up the flavor of the strawberries, and a drop of red food coloring though optional, will brighten the color, if you so desire. This cake is unabashedly pink and it is one of my younger son’s absolute faves for his b-day. But I’m thinking it’d be just as lovely for Valentine’s Day. —Jessie Sheehan

  • Prep time 50 minutes
  • Cook time 30 minutes
  • Serves 16 to 20
  • For the cake
  • 2 cups cake flour, sifted
  • 3/4 cup Dutch Process Cocoa Powder
  • 1 cup packed light brown sugar
  • 1 cup granulated sugar
  • 1 3/4 teaspoons baking powder
  • 1 teaspoon baking soda
  • 1 teaspoon table salt
  • 1 egg, room temperature
  • 2 egg yolks, room temperature, save the whites for the frosting
  • 1 tablespoon pure vanilla extract
  • 1/2 cup vegetable oil
  • 1 cup sour cream, room temperature
  • 1 cup boiling water
  • 1 tablespoon espresso powder
  • For the frosting
  • 1 cup sliced strawberries, plus more for decorating
  • 2 egg whites
  • 1/2 cup plus 2 tablespoons, granulated sugar
  • 1/4 teaspoon cream of tartar
  • 1/4 cup light corn syrup
  • 1/8 teaspoon table salt
  • 1 1/2 teaspoons lemon juice, or more to taste
In This Recipe
  1. For the cake
  2. Preheat the oven to 350°F. Grease a 13-by-9-by-2-in pan with nonstick cooking spray or softened butter and line with parchment paper.
  3. Add the flour, cocoa powder, brown sugar, granulated sugar, baking powder, baking soda, and salt to the bowl of a stand mixer fitted with the paddle attachment; mix on low speed until well combined.
  4. In a small bowl, or in a large 4-cup liquid measuring cup (my preference), add the egg, egg yolks, vanilla, oil, and sour cream and whisk until combined. With the mixer on medium-low speed, slowly pour the wet ingredients into the dry ingredients. Beat until incorporated, scraping down the bowl with a rubber spatula as needed.
  5. In the same small bowl/measuring cup, no need to clean it, combine the boiling water and espresso powder and add to the batter in the mixer bowl. Mix again on medium speed for 30 seconds, until smooth, scraping the bowl with a rubber spatula as needed. The batter will be quite thin
  6. Pour the batter into the prepared pan and bake for 28 to 32 minutes, rotating at the halfway point. The cake is ready when a toothpick inserted in the middle comes out with a moist crumb or two. Let cool completely in the pan. Or let cool enough so you can comfortably handle it, and invert the cake on to a serving plate to continue cooling. If you would rather serve slices directly from the pan, let cool to room temp before frosting.
  1. For the frosting
  2. In a food processor fitted with the metal blade, or in a blender, process the berries until pureed. Place a sieve over a small bowl, pour the puree into the sieve, and using a rubber spatula, press the puree through the sieve to remove the seeds. Set aside.
  3. Add the egg whites, sugar, corn syrup, cream of tartar, and salt in the now-cleaned bowl of the stand mixer and nestle it in a saucepan of simmering water over medium-high heat. Donot allow the bottom of the bowl to touch the water. Whisk until the mixture is just warm to the touch. Remove the bowl from the heat, add the puree and transfer it to the stand mixer fitted with the whisk attachment. Mix on high speed until stiff and glossy, about 7 minutes. Add the lemon juice and whisk a final time to combine.
  4. Once the cake is cool, generously frost it and sprinkle the top with pink sanding sugar. The frosted cake is best served within a few hours with a few sliced strawberries on each plate - or, a scoop of strawberry ice cream - I mean this is a birthday cake, after all.

See what other Food52ers are saying.

  • Jessie Sheehan
    Jessie Sheehan
  • Lisa
  • Marissa
Bio: Jessie Sheehan is a cookbook author, recipe developer, and baker. She is the author of The Vintage Baker (one of the Washington Post’s best cookbooks of 2018 and beloved by Oprah and Nigella) and the co-author of Icebox Cakes (both published by Chronicle Books). She has developed recipes for many cookbooks, besides her own, and has contributed recipes, written and/or created video content for Better Homes & Garden, Rachael Ray Everyday, the Washington Post, Fine Cooking, Yankee Magazine (October 2020) Epicurious, Food52, The Hallmark Channel’s Home & Family Show, The Feed Feed, The Kitchn, TASTE, Chowhound, Yummly, Spruce Eats and Little Sous, among others.

4 Reviews

Lisa May 27, 2020
I baked this for my son's birthday a couple of weeks ago and it was delicious! The cake was perfect but my strawberries were on the tart/unripe side so the frosting didn't have as much strawberry flavor as I would have liked like so I will make this again with more flavorful berries. I will definitely be making this again and again. Thank you Jessie for a great recipe!
Author Comment
Jessie S. May 27, 2020
Yay! Really glad you made this and glad you enjoyed. Sorry about the strawberries. That’s a bummer, but so pleased you’ll make the cake again anyway!
Marissa March 17, 2019
So easy and yummy! I saw this cake on Instagram a few weeks ago and just now got the chance to try it. The cake tastes closer to dark chocolate than milk chocolate, which I like. The frosting is very light and fluffy. My strawberries were more on the sour side so I didn’t need to add the lemon juice. I would defiantly make this cake again.
Author Comment
Jessie S. April 23, 2019
yay! so happy to read this and so sorry i missed it when you first wrote it. XO