• Preheat oven to 350° and grease a 13 x 9 baking dish. Set aside.

For the Brownie Cake

• In a large mixing bowl, whisk flour, sugar, cocoa powder, baking powder and salt together. 
• Pour milk, oil and vanilla into flour mixture, stir until combined then stir in walnuts.
• Add batter mixture to prepared baking dish.

For the Chocolate Pudding

• In a medium mixing bowl, whisk brown sugar and cocoa powder together. 
• Slowly add boiling water into mixture, stir, then carefully pour pudding mixture over brownie mixture.
• Bake for 40 minutes then remove from oven and place on a wire rack to cool. After about 15 minutes, add chocolate chips, white chocolate chips and walnuts on top. Let cool for 30 more minutes.
• Spoon into dessert bowls and spoon additional pudding over the top.
• Serve warm with a scoop of vanilla ice cream.