Melt the chocolate in the microwave for 20 seconds and stir. Then, heat in 15 second intervals and mix well in between until melted. Let it cool.
4 oz Semi-sweet chocolate bar
In a medium bowl, mix the flour, cocoa powder, baking powder, and salt. Set aside.
½ cup All-purpose flour, 3 tablespoon Unsweetened cocoa powder, ¾ teaspoon Baking powder, ½ teaspoon Salt
Using a mixer, beat the butter, brown sugar, and sugar on high for 2 minutes. It will be fluffy. Add in the melted chocolate and the vanilla. Beat on high speed for 1 minute and scrape the bowl.
4 oz Semi-sweet chocolate bar, ¼ cup Unsalted butter, ½ cup Brown sugar, 3 tablespoon White granulated sugar, 1 teaspoon Pure vanilla extract
Add in the egg and mix on medium for 1 minute. Add in the dry ingredients and mix on low until just combined. Add the chocolate chips, Oreo pieces, and Oreo crumbs and mix until just combined.
1 Large egg, ¾ cup Semisweet chocolate chips, ½ cup Oreo pieces, ⅛ cup Oreo crumbs
Preheat the oven to 350°F. Line two cookie sheets with parchment paper. Set aside. While the oven is preheating, chill the brownie cookie dough in the fridge for 10-15 minutes. It should be less of a wet dough. Only the brownie dough needs to chill, the Oreo chocolate chip cookie dough doesn't need to chill.
While the brownie cookie dough is chilling, use a 1 oz cookie scoop and scoop a heaping cookie scoop of the Oreo chocolate chip cookie dough. Place the scoops on a plate. Once the brownie cookie dough is done chilling, do the exact same for that one. You should have two plates full of small cookie dough balls.
Using your hands, take one brownie cookie dough ball and one Oreo chocolate chip cookie dough ball and flatten them together slightly. Take the dough and slightly swirl them together by pinching and folding the dough. Then, roll it into a ball using your hands.
Place 6 cookie dough balls per cookie sheet. Bake one sheet at a time. Bake for 13-15 minutes until the edges are slightly golden and the middle is slightly underdone.
Top the warm cookies with extra Oreo pieces and chocolate chips. Let them cool on the hot pan for 5 minutes before transferring to a cooling rack.