Preheat oven to 350°F (175°C). Grease a 9x9 inch baking pan and line with parchment paper

Melt butter in a saucepan over medium heat. Remove from heat and stir in sugar

Beat in eggs one at a time, then add vanilla

In a separate bowl, whisk together cocoa, flour, salt, and baking powder

Gradually add dry ingredients to wet ingredients, mixing until just combined

Spread evenly in prepared pan

In a medium bowl, cream together softened butter and both sugars until light and fluffy

Beat in egg and vanilla

In separate bowl, whisk together flour, baking soda, and salt

Gradually add dry ingredients to wet ingredients, mixing until just combined

Fold in chocolate chips

Drop cookie dough in small portions over brownie layer and spread gently

Bake for 30-35 minutes until cookie layer is golden and a toothpick inserted comes out with moist crumbs

Cool completely in pan before cutting into squares