Creating these delectable Chocolate Chip Cookie Brownies involves following these simple steps:

1. Preheat Oven: Set your oven to 350°F (175°C) and grease a 9×13 inch baking pan.

2. Prepare the Brownie Batter:
– In a medium saucepan, melt the butter over low heat.
– Stir in the granulated sugar, then let it cool slightly.
– Mix in eggs, one at a time, then add vanilla extract.
– In a separate bowl, combine flour, cocoa powder, salt, and baking powder.
– Gradually incorporate the dry mixture into the wet ingredients until well combined. Set aside.

3. Prepare the Cookie Dough:
– In a large mixing bowl, cream together the room temperature butter, brown sugar, and granulated sugar until fluffy.
– Add the eggs, one at a time, stirring well after each addition, followed by the vanilla extract.
– In another bowl, whisk together flour, baking soda, and salt.
– Gradually blend the dry mixture into the wet ingredients. Fold in the chocolate chips.

4. Assemble the Layers:
– Pour the brownie batter into the prepared baking pan, spreading it evenly.
– Use a spoon or spatula to dollop the cookie dough over the brownie layer. Spread gently to cover, allowing some of the brownie layer to peek through.

5. Bake: Place the assembled layers in the preheated oven and bake for 30-35 minutes, or until golden brown and a toothpick inserted near the center comes out with a few moist crumbs but not wet batter.

6. Cool the Brownies: Remove from the oven and allow the brownies to cool in the pan for about 15 minutes before transferring to a wire rack to cool completely.

7. Slice and Serve: Cut into squares and enjoy!

Following these steps will guide you in creating these incredible Chocolate Chip Cookie Brownies with ease.