Heat the butter and chocolate in a microwave safe bowl for 1 minute. Stir the melted butter and partially melted chocolate until they are well combined. Heat in 20 second increments until the butter and chocolate are completely melted, smooth and well combined. Set aside to cool to warm or room temperature.

In a stand mixer fitted with the whisk attachment, whisk the sugar, eggs and vanilla extract together on low speed until combined, about 30 seconds. Increase the speed to high speed, mixing the ingredients until light, fluffy, pale yellow and doubled in size, about 4-5 minutes.

With the mixer on low, stream in the cooled chocolate butter mixture. Mix on low until well combined. Sift in the cocoa powder, baking powder and salt. Mix on low until well combined. Fold in the flour and mini chocolate chips until just combined. Cover the brownie batter and transfer to the fridge to set for about 30 minutes.

While the brownie cookie batter chills and sets, preheat the oven to 350 F (177 C) for 30 minutes. Line two large baking sheets with parchment paper. Using a medium cookie scoop, scoop 2 tablespoons (30 ml) cookie brownie batter onto the prepared baking sheets about 3 inches apart.

Bake the cookie brownies for 10 minutes. Look for set edges with crinkly, shiny and puffy tops. As soon as the cookies come out of the oven, reshape any cookies using a biscuit or cookie cutter slightly wider than the cookie. Place the cutter over the cookies so the edges of the cookie are inside the cookie/ biscuit cutter. In a circular motion, gently nudge the edges back into a round shape.

Cool the brownie fudge cookies on the hot pan for 10 minutes. Then transfer the cookies to a cooling rack to cool to room temperature.