Preheat oven to 350F. Requires a 9" square our round pan.
Ingredients:

2/3 cup unsweetened cocoa powder (1/3 cup in each step)
3/4 tsp baking powder
3/4 tsp salt
2 large eggs
3/4 cup granulated sugar
6 tbsp unsalted butter, melted and cooled
1/2 cup milk
1 tsp vanilla
1/2 cup walnuts or chocolate chips
3/4 cup light brown sugar
1 1/3 cup boiling water
Directions:
In a bowl sift the flour, 1/3 cup cocoa powder, baking powder and salt.
In another bowl whisk the eggs, granulated sugar, melted butter, milk and vanilla. Add the flour mixture and stir until just combined. Stir in walnuts or chocolate chips and spread into ungreased baking pan.
Boil water.
In another bowl whisk remaining 1/3 cup cocoa powder, brown sugar and water. Gently pour over batter.
Place in preheated oven and bake for 35-40 minutes.
Spoon into bowl and top with vanilla ice cream and enjoy.