• Line a 9 x 13 glass dish with parchment paper or foil. Preheat oven to 350℉.

For the Brownie Part

• Whisk together melted butter and cocoa powder in a medium sized bowl. Then mix in both sugars, salt, vanilla, and eggs. (The secret to glossy brownies is to beat the eggs and sugar together super well).
• Add the flour and gently mix (using a rubber spatula) until almost combined, then fold in chocolate chips.
• Transfer the brownie batter to you prepared dish and spread into a thin layer. Set aside.

For the Cookie Dough

• Using a hand mixer, cream the butter and both sugars on high for 3 minutes or until light and fluffy, scraping the sides of the bowl as needed.
• Mix in the vanilla and egg. Then, add the baking soda, salt, and baking powder. Mix until combined.
• Add the flour and mix until almost combined, then fold in the chocolate chips, reserving a few to sprinkle on top later.
• Use your rubber spatula to spoon small clumps of dough onto the brownie layer. You won't really be able to spread it, so just try to flatten the clumps some. You don't need full coverage, having a visual mix of the brownie and cookie layer will make it look good. (It won't look great right now, but we promise you're on the right path).
• Cover with foil and bake for 20 minutes. Uncover, then bake for 20 more minutes.
• Remove from oven and using the parchment paper or foil, lift out of the dish to cool. Allow to fully cool before cutting. (Don't cut into it when it's warm, it will be too soft).