Step 1: Prepare the Batter
Preheat Your Oven: Begin by preheating your oven to 350°F (175°C). Grease a 9-inch round baking dish or an 8×8-inch square baking dish.
Mix Dry Ingredients: In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, cocoa powder, baking powder, and salt until well combined.
Combine Wet Ingredients: In a separate bowl, mix together the milk, melted butter, and vanilla extract.
Combine Mixtures: Pour the wet ingredients into the dry ingredients and stir just until combined. If you’re using chopped nuts, fold them into the batter at this stage.
Step 2: Create the Fudge Layer
Pour Batter Into Dish: Spoon the batter into the prepared baking dish, spreading it evenly.
Mix Sauce Ingredients: In a small bowl, combine the brown sugar and cocoa powder. Sprinkle this mixture evenly over the top of the batter.
Add Hot Water: Carefully pour the hot water over the batter. Do not stir; the magic happens in the oven, where the pudding forms beneath the cake!
Step 3: Bake