Simply the Best Chocolate Cake: The Ultimate One-Bowl Texas Sheet Cake with Pourable Fudge Icing – Gooey, Moist, and Irresistible

• For the Cake
• 1 cup (227g) unsalted butter
• 4 oz (113g) semi-sweet or dark chocolate, very finely chopped
• 3/4 cup (60g) natural cocoa powder
• 1 cup (240ml) hot, freshly brewed coffee (or hot water)
• 2 cups (400g) granulated sugar
• 1 tsp coarse kosher salt (use 1/2 tsp if using fine table salt)
• 1 tbsp vanilla extract
• 3 large eggs, cold, lightly beaten
• 1/2 cup (120ml) buttermilk (or make your own: 1/2 cup (120ml) whole milk mixed with 1 1/2 teaspoons (7.5ml) lemon juice or white vinegar; let sit for 5 minutes until slightly thickened)
• 2 cups (250g) all-purpose flour (gently spooned into the cup measure and leveled with a knife, to avoid overpacking the flour)
• 2 tsp baking soda
• 1 tsp baking powder
• *Optional:* 1 tsp espresso powder for enhanced chocolate depth
• For the Pourable Fudge Icing
• 14 tbsp (198g) unsalted butter
• 1/4 cup (heaping) (20g) natural cocoa powder
• 1/4 tsp kosher salt
• 6 tbsp (90ml) milk
• 1 tsp vanilla extract
• 3 cups (360g) powdered sugar (plus more if needed for consistency)

Instructions

1. 1

   Prepare the pan: Preheat your oven to 350°F (175°C). Line a 13x18-inch (33x46cm) half-sheet pan with parchment paper, leaving an overhang on the sides for easy cake removal.

2. 2

   Make the chocolate base: In a medium saucepan, melt the butter over low heat. Remove from heat, add the chopped chocolate, and let sit for 1 minute. Stir until fully melted and smooth. Stir in the cocoa powder until the mixture resembles a thick ganache.

3. 3

   Add the liquids: Whisk in the hot coffee, sugar, salt, and vanilla. Add the eggs and buttermilk, whisking promptly to prevent the eggs from scrambling.

4. 4

   Combine the dry ingredients: Sift the flour, baking soda, and baking powder directly into the wet ingredients. Whisk until smooth, then give the batter a few extra strokes to aerate. Make sure to whisk for no more than 30–40 seconds after adding dry ingredients. Overmixing can lead to a denser cake.

5. 5

   Bake: Pour the batter into the prepared pan and bake for 13–18 minutes. Begin checking at 13 minutes; the cake should spring back lightly when pressed, with a toothpick inserted into the centre coming out with a few moist crumbs but not wet batter.

6. 6

   Make the pourable fudge icing: In a medium saucepan, melt the butter over low heat. Remove from heat and stir in the cocoa powder until smooth and thick. Add the salt, milk, and vanilla, stirring well. Whisk in the powdered sugar in three additions until smooth and pourable. Adjust with more powdered sugar if needed.

7. 7

   Pour the warm icing over the cooled cake, spreading it evenly. Top with sprinkles, chopped toasted nuts, or a drizzle of extra ganache for added texture.