- 1 cup all-purpose flour
- 2 teaspoons baking powder
- 3/4 cup white sugar
- 2 tablespoons unsweetened cocoa powder
- 1/4 teaspoon salt
- 1/2 cup milk
- 2 tablespoons butter, melted
- 1 cup chopped walnuts
- 1/4 cup unsweetened cocoa powder
- 1 cup packed brown sugar
- 1 3/4 cups hot water
- Preheat oven to 350 degrees F (175 degrees C).
- Grease a 9×9-inch baking pan.
- Whisk together flour, baking powder, white sugar, 2 tablespoon cocoa powder, and salt in a large bowl.
- Stir in milk and butter until smooth.
- Fold in walnuts until just combined.
- Spread batter evenly in the prepared baking pan.
- Mix 1/4 cup cocoa and brown sugar in a small bowl; sprinkle mixture on top of the batter.
- Pour hot water over the batter.
- Bake in the preheated oven until the center of the cake is almost set, about 45 minutes. Brown sugar, cocoa, and hot water will combine to form a chocolate sauce that will settle to the bottom of the cake during baking.
- Best served warm.