Description
A dense, moist, and utterly fudgy chocolate sheet cake with a warm, poured chocolate glaze that sets into a thin, crackly shell. This one-bowl recipe is easier than boxed mixes and tastes better than bakery cakes.
Ingredients
Scale
- 1 ½ cups (190g) all-purpose flour
- 1 ½ cups (300g) granulated sugar
- ¾ cup (65g) unsweetened cocoa powder (Dutch-processed preferred)
- 1 tsp baking powder
- 1 ½ tsp baking soda
- 1 tsp salt
- 2 large eggs (room temperature)
- 1 cup (240ml) buttermilk
- ½ cup (120ml) vegetable oil
- 1 cup (240ml) hot coffee or boiling water
- 2 tsp vanilla extract
- 1 ½ cups (270g) semi-sweet chocolate chips
- ½ cup (120ml) heavy cream
- 2 tablespoons unsalted butter
- a pinch of salt (for frosting)
- flaky sea salt (optional, for topping)
Instructions
- Preheat oven to 350°F (175°C). Grease a 9×13 inch baking pan and line the bottom with parchment paper.
- In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and 1 tsp salt until no lumps remain.
- Add the eggs, buttermilk, vegetable oil, and vanilla extract to the dry ingredients. Whisk until the batter is smooth and thick.
- Slowly pour in the hot coffee or boiling water while whisking constantly. The batter will become thin and watery; 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 with moist crumbs (not wet batter). The cake will pull away slightly from the edges.
- While the cake bakes, make the frosting: In a small saucepan, heat the heavy cream over medium heat until it just starts to simmer. Pour the hot cream over the chocolate chips in a heat-proof bowl and let sit for 2 minutes.
- Add the 2 tablespoons of butter and a pinch of salt to the chocolate mixture. Stir gently until smooth and glossy.
- Once the cake is done, let it cool in the pan for 10 minutes.
- Pour the warm chocolate frosting over the cake and spread to the edges. Sprinkle with flaky sea salt if desired.
- Let the cake cool completely before cutting to allow the frosting to set into a crackly shell.
Notes
Do not overbake the cake, as it continues to cook in the hot pan. Use hot coffee to ‘bloom’ the cocoa powder for deeper flavor, though boiling water can be substituted. The cake keeps well at room temperature for 2 days or in the fridge for up to 5 days. For gluten-free, use a 1:1 gluten-free flour blend. For dairy-free, substitute buttermilk with almond/oat milk plus vinegar and butter with coconut oil.
- Prep Time: 10 minutes
- Cook Time: 35 minutes
- Category: Dessert
- Cuisine: American
Nutrition
- Serving Size: 1 square (out of 12)
- Calories: 380
- Sugar: 38
- Sodium: 350
- Fat: 18
- Saturated Fat: 8
- Carbohydrates: 52
- Fiber: 3
- Protein: 5
Keywords: chocolate cake, sheet cake, fudgy cake, easy dessert, one-bowl cake, chocolate glaze, homemade cake, holiday dessert