3 brownies with chocolate buttercream Recipes

red velvet cake mix, butter, egg, water, semi-sweet chocolate chips, walnuts, chopped (optional), unsalted butter, at room temperature, powdered sugar, vanilla extract, white chocolate, melted, heavy whipping cream

cocoa, baking soda, butter or margarine, melted and divided, boiling water, sugar, eggs, slightly beaten, all-purpose flour, vanilla extract, salt, semi-sweet chocolate chips, buttercream frosting (follows) (or you can use your favorite store-bought chocolate frosting)