Step 1: Prepare the Brownie Batter

1. Preheat oven to 350°F (175°C) and line a 9×13-inch baking pan with parchment paper.
2. Mix melted butter, granulated sugar, and brown sugar until smooth.
3. Add eggs and vanilla extract, beating until combined.
4. Sift in flour, cocoa powder, salt, and baking powder. Fold in gently.
5. Stir in chocolate chips (if using). Spread half of the batter in the pan.

Step 2: Make the Cheesecake Layer

1. In a bowl, beat softened cream cheese with sugar until smooth.
2. Add the egg and vanilla extract, mixing until creamy.
3. Spread over the brownie batter in the pan.

Step 3: Prepare the Cherry Topping

1. In a saucepan, combine cherries, sugar, cornstarch, and lemon juice.
2. Cook over medium heat until the mixture thickens (about 5-7 minutes).
3. Let cool slightly before drizzling over the cheesecake layer.

Step 4: Add the Final Brownie Layer

1. Spoon the remaining brownie batter over the cheesecake and cherry layers.
2. Use a toothpick to create a marbled effect by swirling the layers.

Step 5: Bake and Cool

1. Bake for 35-40 minutes or until a toothpick inserted in the center comes out with a few moist crumbs.
2. Let the brownies cool in the pan for 1 hour, then refrigerate for another 1-2 hours.
3. Slice and serve chilled.