Name: Ultimate Chocolate Sheet Cake
Prep time: 20 min
Cook time: 20 min
Total time: 188 min
Yield: 28
Cuisine: International
Ingredients: 1 ⅓ cups semisweet chocolate wafers, chunks, chips, or chopped semisweet chocolate; 4 tbsp butter, room temperature; ¾ cup vegetable oil; ¾ cup water; ½ cup King Arthur Triple Cocoa Blend or Dutch-process cocoa; 2 cups King Arthur Unbleached All-Purpose Flour; 2 cups granulated sugar; ½ tsp baking soda; ½ tsp table salt; 2 large eggs, at room temperature; ¼ cup buttermilk or yogurt, at room temperature; 2 large egg yolks, at room temperature; 2 tsp vanilla extract; 2 cups semisweet chocolate wafers, chunks, chips, or chopped semisweet chocolate; 2 tbsp light corn syrup; 1 tsp vanilla extract; ⅔ cup heavy cream; 1 cup confectioners' sugar; ½ cup unsweetened cocoa, Dutch-process or natural

Ultimate Chocolate Sheet Cake

An incredibly moist, fudgy chocolate sheet cake topped with a glossy, rich ganache-like icing. Perfect for parties and chocolate lovers.

Prep20 min

Cook20 min

Total3h 8m

DifficultyMedium

Servings28

This massive chocolate sheet cake delivers deep cocoa flavor and an ultra-tender crumb. The icing sets to a dense, fudge-like layer that perfectly complements the soft cake.

Baked in a half-sheet pan, this cake feeds a crowd with minimal effort. The warm chocolate mixture is stirred into the dry ingredients for a batter that bakes up evenly and stays moist for days.

Method

Preheat the oven to 350°F. Lightly grease a half-sheet pan (13x18 inches), line with parchment paper, and grease the parchment as well.
In a medium saucepan or microwave-safe bowl, combine the chocolate (1 1/3 cups), butter, oil, water, and cocoa. Heat gently, stirring often, until the mixture is smooth. Transfer to a large mixing bowl.
In a separate bowl, whisk together the flour, sugar, baking soda, and salt until evenly combined.
Add the flour mixture to the chocolate mixture and stir just until combined—do not overmix.
In a small bowl, whisk together the buttermilk, eggs, egg yolks, and vanilla. Pour into the batter and stir just until incorporated.
Pour the batter into the prepared pan and spread it evenly to the edges.
Bake for 18 to 20 minutes, until a toothpick inserted in the center comes out clean. Remove from oven and let the cake cool completely in the pan.
For the icing: In a microwave-safe bowl, combine the chocolate (2 cups), corn syrup, vanilla, and heavy cream. Microwave until the cream is very hot and the chocolate has softened, then stir until smooth. If needed, reheat briefly.
Sift the confectioners' sugar and cocoa over the chocolate mixture and beat until smooth and glossy.
Spread the icing evenly over the cooled cake. Let it set for 30 to 60 minutes, then slice and serve.

💡 Tips

For even easier removal, let the cake cool completely and then freeze it for 15 minutes before icing.
Use a thin spatula to spread the icing smoothly; the gloss will be perfection.
Store leftovers covered at room temperature for up to 3 days.

Ultimate Chocolate Sheet Cake

Ingredients

Cake

Icing

Method

💡 Tips

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