Description
A rustic, deeply chocolatey sheet cake that is incredibly moist thanks to blooming cocoa with boiling water and coffee. It features a rich, thick fudge icing that sets into a slightly crisp shell, making it perfect for crowds and make-ahead baking.
Ingredients
Scale
- 2 cups (250g) all-purpose flour
- 1 ½ cups (300g) granulated sugar
- ¾ cup (75g) unsweetened cocoa powder
- 1 ½ teaspoons baking soda
- 1 ½ teaspoons baking powder
- 1 teaspoon salt
- ½ cup (115g) butter, melted
- 2 large eggs, room temperature
- 1 teaspoon vanilla extract
- 1 cup (240ml) whole milk
- 1 cup (240ml) boiling water
- 1 cup (240ml) strong brewed coffee, cooled slightly
- 1 teaspoon white vinegar
- ½ cup (115g) unsalted butter (for icing)
- ¾ cup (75g) unsweetened cocoa powder (for icing)
- 3 cups (360g) powdered sugar
- 3–4 tablespoons milk (for icing)
- 1 teaspoon vanilla extract (for icing)
- ¼ teaspoon salt (for icing)
Instructions
- Preheat oven to 350°F (175°C). Grease a 9×13 inch baking pan and dust with flour or cocoa powder.
- In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt until no lumps remain.
- Add the melted butter, eggs, vanilla, milk, and vinegar to the dry ingredients. Beat on medium speed for about 2 minutes, or mix vigorously by hand, until incorporated.
- Stir in the boiling water (or coffee) by hand. The batter will become thin; this is normal. Pour the batter into the prepared pan.
- Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean or with moist crumbs.
- Let the cake cool in the pan for 10 minutes, then turn it out onto a wire rack to cool completely.
- While the cake cools, make the icing: In a small saucepan, melt the butter over medium heat. Add the cocoa powder and stir until smooth. Remove from heat.
- Stir in the powdered sugar, 3 tablespoons of milk, vanilla, and salt. Add more milk gradually until the icing reaches a spreadable, pourable consistency.
- Pour the warm icing over the completely cooled cake and spread to the edges.
- Let the icing set for 15-20 minutes before slicing into squares and serving.
Notes
The boiling water blooms the cocoa powder for intense flavor and moisture. Do not skip this step. The cake must cool completely before icing to prevent the icing from melting. Coffee enhances the chocolate flavor but is optional; hot water can be used as a substitute. The cake keeps well at room temperature for 3 days or in the fridge for 5 days.
- Prep Time: 15 minutes
- Cook Time: 35 minutes
- Category: Dessert
- Cuisine: American
Nutrition
- Serving Size: 1 slice
- Calories: 380
- Sugar: 38
- Sodium: 280
- Fat: 18
- Saturated Fat: 10
- Carbohydrates: 52
- Fiber: 2
- Protein: 4
Keywords: chocolate cake, sheet cake, fudge icing, moist chocolate cake, easy dessert, party cake, homemade cake