Preheat the oven to 350 degrees. Line a 9x13 baking dish with parchment paper. Use a mixer to beat the butter, sugar and brown sugar together until light and fluffy. Beat in the eggs, adding one at a time until combined. Add in the vanilla, baking soda, salt and mix until combined. Gradually mix in the flour ingredients until combined. Fold in the chocolate chips. Spread the dough into the pan. Bake the dough into the oven for 25 minutes or until the edges are lightly golden brown and the center is almost set. Allow to cool while you make the brownie batter.
Brownie Batter Instructions * Melt the butter in a medium pot on low-medium heat. Whisk in the chocolate chips until they are smooth. Remove the pot from the heat and set aside. Place the eggs, sugar, salt and vanilla extract into a medium bowl and whisk together. Gradually whisk the egg mixture into the chocolate mixture. Gradually whisk in the cocoa powder and flour until combined and smooth. Spread the brownie batter onto the top layer of the cookie layer. Bake in the oven for 25-30 minutes or until a toothpick comes out clean in the middle. Place on the counter to cool completely.
Chocolate Chip Cookie Dough Frosting Instructions * Use a mixer to beat together the butter, sugar and brown sugar until combined and smooth. Add in the milk, vanilla and salt and mix until combined. Fold in the chocolate chips. Spread the frosting onto the top of the brownie layer. Place into the fridge overnight to allow the frosting to harden before cutting. Serve and enjoy!