Preheat the Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan or line with parchment paper.

Prepare the Brownie Base: In a large bowl, whisk melted butter and sugar until smooth. Add eggs one at a time, beating well after each. Stir in vanilla extract. In a separate bowl, sift together flour, cocoa powder, salt, and baking powder. Fold dry ingredients into the wet mixture until combined. Stir in chocolate chips if using.

Prepare the Cheesecake Layer: In a medium bowl, beat cream cheese, sugar, egg, and vanilla until smooth.

Prepare the Raspberry Swirl: If using fresh raspberries, lightly mash them with a fork. If using frozen raspberries, thaw and mash with sugar if desired.

Assemble the Brownies: Pour half of the brownie batter into the prepared pan and spread evenly. Carefully spread the cream cheese mixture over the brownie layer. Drop the remaining brownie batter on top in dollops. Use a knife or skewer to swirl the brownie and cheesecake layers together. Drop raspberry puree over the top and swirl lightly.

Bake: Bake for 35–40 minutes, or until a toothpick inserted into the brownie portion comes out with a few moist crumbs. Avoid overbaking to keep it fudgy.

Add White Chocolate: Melt white chocolate in a microwave-safe bowl in 20-second intervals, stirring in between, until smooth. Drizzle or spread melted white chocolate over the top of the cooled brownies for a beautiful finish.

Cool and Slice: Allow brownies to cool completely in the pan before slicing into 16 squares.