#### Make the Red Velvet Brownie Base
**Preheat the oven**
Preheat your oven to 350°F (175°C). Line a 9x9-inch baking pan with parchment paper, leaving an overhang for easy removal.
**Mix wet ingredients**
In a large bowl, whisk together the melted butter, sugar, eggs, vanilla extract, and red food coloring until smooth and well combined.
**Add dry ingredients**
Sift in the flour, cocoa powder, and salt. Stir until just combined, being careful not to overmix. Set aside 2–3 tablespoons of the batter for swirling.
**Spread batter**
Pour the remaining batter into the prepared baking pan, spreading it evenly with a spatula.
#### Make the Cheesecake Swirl
**Mix the cheesecake layer**
In a separate bowl, beat the cream cheese and sugar with a hand mixer or stand mixer until smooth. Add the egg and vanilla extract, mixing until fully incorporated.
**Layer and swirl**
Spoon the cheesecake mixture over the red velvet batter in dollops. Add the reserved red velvet batter on top. Use a knife or skewer to gently swirl the layers together, creating a marbled effect.
#### Bake and Cool
**Bake**
Bake for 30–35 minutes, or until the edges are set and a toothpick inserted into the center comes out with a few moist crumbs.
**Cool**
Let the brownies cool completely in the pan, then refrigerate for at least 1 hour before slicing.