Preheat oven to 350 F. In a large bowl, whisk together flour, sugar, cocoa powder, salt, and baking powder.
Add in eggs, melted butter, melted chocolate and vanilla extract, whisk until smooth. Spread brownie batter into a greased baking dish. Bake for 25-30 minutes. Let cool completely.
Place flour into a microwave safe bowl, heat in the microwave for 40 seconds, set aside. In a large bowl, beat softened butter with both sugars until fluffy. Add in milk and vanilla extract, beat until smooth. Add in the heated flour, beat until incorporated. Fold in chocolate chips.
When cooled, spread cookie dough over brownie layer and refrigerate until set. Cut into squares.
