In a large bowl, add in the 16 ounces cream cheese. Beat with a hand mixer on medium until smooth and creamy.
Add in the 3/4 cup granulated sugar and beat until incorporated.
Add in the 1/2 teaspoon mint extract, 1 - 3 drops leaf green gel food coloring, and 2 large eggs, one at a time. Beat in the egg until combined before adding the next egg. Scrape down the sides of the bowl before adding the second egg. If you would like to add more food color, add it in with the second egg. Set the cheesecake batter aside.
Brownies
Preheat the oven to 350 degrees F. Spray an 8x8 inch pan with nonstick baking spray. Place a strip of parchment paper in the pan to cover the bottom and leave a little overhang on two of the sides to use as handles to pull the brownies out of the pan once cooled. Set aside.
Add the ¾ cup butter and 4 ounces semi-sweet baking chocolate to a microwave-safe bowl. Microwave in 30-second intervals and stir after each interval until the chocolate is completely melted.
Pour the butter and chocolate into a large mixing bowl. Add in the ¾ cup granulated sugar, ½ cup light brown sugar, 2 large eggs, and 2 teaspoons vanilla extract. Using a hand mixer, beat on medium for about 1 to 2 minutes until lighter in color and thick.
Add in the ½ cup unsweetened cocoa powder, ½ cup all-purpose flour, ½ teaspoon baking powder, and ½ teaspoon salt. Beat just until the flour is incorporated.
Add 3/4 of the brownie batter to the prepared pan. Gently spread the brownie batter out evenly using a spatula.
Add in 3/4 of the cheesecake batter and spread it out.
Add dollops of brownie batter and cheesecake batter on top, letting some of the brownie batter overlap the cheesecake batter and vice versa.
Using a butter knife or skewer, swirl just the cheesecake and top brownie layers together. I make about 5 to 6 passes through the layers to swirl it together. Give the brownies a tap to help everything settle.
Place in the 350 degrees F oven and bake for 10 minutes and then reduce the oven to 325 degrees F and bake 40 to 45 minutes until the brownies and cheesecake are both set. Allow the brownies to cool to room temperature before refrigerating overnight to set up.
Slice and cut.
Cover the brownies with plastic wrap or place them in an airtight container and store them in the refrigerator.
Notes
Storage: Store in an airtight container or wrapped tightly in its pan with plastic wrap in the refrigerator for up to 5 days.