Preheat oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper or lightly grease it.
In a saucepan over low heat, melt the butter. Remove from heat and stir in 1 cup sugar, 2 eggs, and 1 teaspoon vanilla.
Whisk in cocoa powder, flour, salt, and baking powder until combined. Spread most of the brownie batter into the prepared pan, reserving about 1/4 cup for topping.
In a separate bowl, beat cream cheese until smooth. Add 1/4 cup sugar, 1 egg, and 1/2 teaspoon vanilla extract. Mix until fully combined.
Gently spread the cream cheese layer over the brownie batter in the pan.
Drizzle caramel sauce over the cheesecake layer and swirl gently with a knife.
Dollop the reserved brownie batter on top and swirl again slightly for a marbled effect.
Bake for 35–40 minutes or until the center is set and a toothpick comes out with a few moist crumbs.
Cool completely in the pan, then refrigerate for at least 2 hours before slicing.
Notes
For easier swirling, warm the caramel sauce slightly before using.
Chill before cutting to get clean layers and edges.
Store leftovers in an airtight container in the fridge for up to 5 days.