Preheat oven to 350°F. Grease an 8x8x2-inch baking pan. Set aside.
In a medium mixing bowl stir together flour, granulated sugar, 2 tablespoons cocoa powder, baking powder, and salt. Stir in the milk, oil, and vanilla. Fold in the walnuts. Pour batter into the prepared pan.
In a small mixing bowl stir together the brown sugar and the 1/4 cup cocoa powder. Add the boiling water. Once combined slowly pour over batter in pan. Bake in a 350° oven for 40 minutes. Cool in pan on a wire rack for 45 to 60 minutes. Serve warm. If desired, serve with ice cream.
Serves 6 to 8
Prep Time: 10 mins.
Cook Time: 40 mins.