Chocolate

Easy Chocolate Sheet Cake

by:
May 14, 2017
8 Ratings
Easy Chocolate Sheet Cake
Photo by Posie Harwood
Author Notes

This simple, and delicious, chocolate cake recipe uses a neat one-bowl technique that makes it fast and no fuss to mix up at the merest hint of a chocolate craving. I've adapted it from an old Parkay margarine recipe. —Posie (Harwood) Brien

  • Makes one 9" x 13" cake
Ingredients
  • For the cake
  • 1 cup water
  • 1/2 cup (8 tablespoons) unsalted butter
  • 1 1/2 ounces unsweetened chocolate
  • 2 cups (8 1/2 ounces) flour
  • 2 cups (14 ounces) granulated sugar
  • 2 eggs
  • 1/2 cup sour cream
  • 3/4 teaspoon espresso powder (optional, but enhances chocolate flavor)
  • 1 teaspoon baking soda
  • 1/2 teaspoon salt
  • For the frosting
  • 1 cup (16 tablespoons) unsalted butter
  • 6 tablespoons milk
  • 1 1/2 ounces unsweetened chocolate
  • 4 1/2 cups (About 16 ounces) sifted confectioners' sugar (start with less and add as needed)
  • 1 teaspoon vanilla
In This Recipe
Directions
  1. Preheat the oven to 375 degrees F. Grease and flour a 9" x 13" pan.
  2. To make the cake: In a large saucepan, combine the water, butter, and chocolate. Bring to a boil, stirring occasionally, then remove from the heat.
  3. Add the flour, sugar, baking soda, salt, and espresso powder (if using) to the saucepan and whisk to combine.
  4. Add the eggs and sour cream and mix well. Pour the batter into the prepared pan and bake for 20-25 minutes, until the cake begins to pull away from the sides of the pan and springs back when touched lightly.
  5. To make the frosting: Add butter, milk, and chocolate to a saucepan and bring to a boil, stirring to melt the chocolate.
  6. Remove from the heat and add the sugar -- you may not need all the sugar so start with half or so and add to get to the right consistency. Beat with a handheld mixer (or transfer to the bowl of a stand mixer) until the frosting is smooth. If it is too liquidy, refrigerate the frosting for a bit and then try beating again. It'll thicken up as it cools and become nicely spreadable. Mix in the vanilla once the consistency is right.
  7. Spread the frosting over the cake, then cut into squares and serve.
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  • Barbara Sunday
    Barbara Sunday
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    Shelley Lawrence
  • Pam Pershan Hochman
    Pam Pershan Hochman
  • Jessica
    Jessica
  • Posie (Harwood) Brien
    Posie (Harwood) Brien
Posie (Harwood) Brien
I like warm homemade bread slathered with fresh raw milk butter, ice cream in all seasons, the smell of garlic in olive oil, and sugar snap peas fresh off the vine.

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20 Reviews

Barbara S.
Barbara S. October 21, 2017
Is the 1.5 oz of chocolate hard chocolate or powdered chocolate? Thank you!
 
Barbara S.
Barbara S. October 21, 2017
Is the 1.5 oz of chocolate hard chocolate or powdered chocolate? Thank you!
 
nanci
nanci June 25, 2017
Thought there was too much butter in frosting.
BTW-I added extra oz of chocolate in cake and frosting
 
Alexis
Alexis June 6, 2017
Perfect! Never made it with less.
 
Shelley L.
Shelley L. June 6, 2017
How did it come out?
 
Alexis
Alexis June 5, 2017
I added twice the amount.
 
Shelley L.
Shelley L. June 5, 2017
I made it Friday and thought the Sam thing. My people liked it but I might add more chocolate next time
 
Pam P.
Pam P. June 4, 2017
It seems like such a small amount of chocolate. Has anyone added more?
 
Shelley L.
Shelley L. June 1, 2017
Do you take the cake out of the pan before frosting it?
 
Author Comment
Posie (.
Posie (. June 1, 2017
I don't -- it's simpler to just frost and serve from the pan!
 
Jessica
Jessica June 1, 2017
Can it be done with regular cream instead of sour cream?
 
Author Comment
Posie (.
Posie (. June 1, 2017
Hm, not sure how that would affect the texture because it would make the batter much looser.
 
Jessica
Jessica June 1, 2017
Then I will try to make my own sour cream and see how that works. Thanks for your reply!
 
Alexis
Alexis May 29, 2017
While still recuperating from wrist surgery, I made this cake with my non-dominant hand and added chopped bittersweet chocolate pieces. Didn't frost yet still a huge success!
 
witloof
witloof May 28, 2017
Just to let you know that everyone loved this cake and I received many compliments and many requests for the recipe. I topped it with cream cheese frosting. It went so fast that I didn't actually get to taste it myself! I'm contemplating replacing half a cup of flour with a half cup of cocoa powder next time I make it.
 
Susanne
Susanne May 26, 2017
There are 6 1/2 cups of sugar in this recipe? Am I reading that right?
 
Author Comment
Posie (.
Posie (. May 26, 2017
That includes the frosting! And it's 4 1/2 cups of sifted confectioners sugar in the frosting -- meaning sifted before measuring so pretty much a standard buttercream sugar amount :)
 
Susanne
Susanne May 26, 2017
Thanks for the response! :-)
 
Therese
Therese May 31, 2017
For what it's worth, I cut back the sugar in the cake by 1/2 cup and it turned out fine.
 
witloof
witloof May 26, 2017
I have this in the oven now after looking for a recipe for a chocolate cake that would feed a crowd, transport easily, and come together quickly. Thanks!