Overhead shot of yellow sheet cake recipe
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4.5 from 2 votes

Yellow Sheet Cake With Chocolate Sour Cream Frosting

Yellow Sheet Cake with Chocolate Sour Cream Frosting is a perfect cake to serve at parties! Your guests will love it! 
Prep Time1 hr
Cook Time30 mins
Total Time1 hr 30 mins
Course: Dessert
Cuisine: American
Keyword: yellow Sheet Cake
Servings: 30 servings
Calories: 274kcal
Author: Jennifer Farley

Ingredients

For the cake:

  • baking spray with flour
  • 15 ounces all-purpose flour (approximately 3 cups)
  • 1 1/2 teaspoons baking powder
  • 1 teaspoon baking soda
  • 1 teaspoon kosher salt
  • 1 cup buttermilk
  • 1/3 cup vegetable oil, see notes
  • 1 1/2 teaspoons pure vanilla extract
  • 6 ounces unsalted butter, room temperature
  • 1 1/2 cups granulated sugar
  • 1/3 cup packed light brown sugar
  • 4 large egg yolks
  • 2 large eggs

For the frosting:

  • 4 ounces unsalted butter
  • 2 ounces unsweetened chocolate, chopped
  • 1/3 cup Dutch-processed cocoa powder, sifted
  • 2 teaspoons pure vanilla extract
  • 10 ounces confectioners' sugar, sifted (approximately 2 cups)
  • 2/3 - 1 cup sour cream

Instructions

Prepare the cake:

  • Preheat the oven to 350 degrees F. Lightly coat an 18x13 inch half-sheet pan with baking spray (the kind with flour incorporated works best), top with parchment paper, and coat with additional baking spray.
  • In a medium-sized bowl, whisk together the flour, baking powder, baking soda, and kosher salt. Set aside. In a large liquid measuring cup, combine the buttermilk, vegetable oil and vanilla extract.
  • In a stand mixer fitted with the paddle attachment, combine the butter, granulated sugar, and brown sugar on low speed and then slowly turn the mixer up to high speed and cream for 3-4 minutes until light and fluffy. Scrape down the sides. Turn down the speed to medium and add the eggs and yolks, one at a time, allowing each to fully incorporate, over the course of 4-5 minutes. Scrape down the sides all the way to the bottom. Turn the mixer speed down to low and alternate between adding the dry and wet ingredients, starting and ending with the dry.
  • Scrape the batter into the prepared sheet pan, using a spatula (preferably an offset spatula) to even out the top of the cake. Make sure the batter is spread evenly into the 4 corners of the pan. Bake for 20-25 minutes, rotating the pan once halfway through, until the top is golden and springy, and a toothpick comes out clean from the center. Remove from the oven and allow to cool completely. The cake can be prepared 24 hours in advance (or longer, if frozen).

Prepare the frosting:

  • In a double boiler (or in a medium heatproof bowl set over a saucepan of barely simmering water), melt the butter and chocolate together until smooth, stirring constantly. 
  • Once combined, pour into a large bowl and whisk in the cocoa powder and vanilla extract. Whisk in half of the sugar and sour cream (the frosting will be very thick). 
  • Keep adding the sugar and sour cream until the desired texture and flavor is reached. If the frosting seems too thin at any time, additional sugar can be sifted in. Or, to keep the sweetness level the same, place the frosting in the refrigerator and chill for 10-15 minutes, stirring every 5 minutes. This will allow the butter to firm up.

Frost the cake:

  • Gently run a pairing knife or offset spatula along the edges of the pan to detach any portion of the cake that might have attached itself. Next, place a clean dishtowel on top of the cake, and top that with another sheet pan or a large cutting board. Pick up the pan and gently flip it over so that the cake inverts onto the dish towel.
  • Peel away the parchment paper, and then gently flip the cake on a large serving platter, cutting board, or back into the same sheet pan (place the board or pan directly against the cake before inverting).
  • Frost the cake evenly and cut into squares. Serve.

Notes

The original Bon Appetit sheet cake recipe calls for 1/3 cup vegetable oil, but I used avocado oil instead for health reasons (not that this is a healthy cake). Avocado oil has a neutral flavor which works well in this cake; you can use either. I did not include avocado oil in the main ingredient list because I realize it's an expensive ingredient that most people do not keep on hand.
  
Sheet cake recipe adapted from Bon Appetit. Chocolate Sour Cream Frosting Adapted from Epicurious.

Nutrition

Calories: 274kcal | Carbohydrates: 31g | Protein: 2g | Fat: 11g | Saturated Fat: 6g | Cholesterol: 56mg | Sodium: 130mg | Potassium: 65mg | Sugar: 20g | Vitamin A: 275IU | Calcium: 23mg | Iron: 1.2mg