Brownies

1. Preheat the oven to 350°F. Generously grease an 8-inch baking pan and line with parchment paper.
2. Chop the chocolate into smaller pieces and melt the chocolate in a microwave-safe bowl for approximately 2 minutes at 50% power. Stir every 30 seconds until completely melted and smooth. Set aside to cool.
3. Melt the butter in a microwave-safe bowl and combine with the granulated sugar; beat together until well combined.
4. Next add the eggs and egg yolk and beat for 60-90 seconds at a higher speed until the batter is fluffy (texture resembling a cake batter). Then add the vanilla extract and melted chocolate and beat until combined.
5. Combine the dry ingredients in a separate bowl and stir to combine. Add the dry ingredients to the batter and mix just until combined. Fold in the chocolate chips with a spatula. Set aside.

Cheesecake filling

1. In a mixing bowl, beat the cream cheese and sugar until well combined and free of any lumps, scraping down the bowl as needed.
2. Next beat in the egg and vanilla extract until well combined and completely smooth. Set aside.

To assemble:

1. Spread the 2/3 of the brownie batter in the prepared pan. Then spoon 2/3 of the cheesecake batter over the brownies. Finally, spoon the remaining brownie batter and cheesecake batter and swirl with a knife.
2. Bake at 350°F for 35-40 minutes. Toothpick should still be somewhat gooey but not wet in the center. Remove from the oven and allow to cool prior to cutting. Store in an airtight container.