heat your oven to 350°F (175°C). Line a 9 inch square baking pan with parchment paper and lightly butter the parchment.
Melt the butter in a small saucepan over low heat, and set it aside to let it cool.
8 tablespoons (113 grams) unsalted butter
Sift or whisk together the flour, cocoa powder, baking powder, and salt.
1 cup (125 grams) all purpose flour, ¼ cup (24 grams) unsweetened cocoa powder, ½ teaspoon baking powder, ¼ teaspoon salt
Beat the eggs and sugar together until lightened in a medium bowl. Then add the melted and cooled butter, red food coloring, vanilla, and vinegar.
2 large eggs, 1 cup (200 grams) granulated sugar, 1 tablespoon red food coloring, 1 teaspoon vanilla extract, 1 teaspoon white vinegar
Add the dry ingredients into the wet mixture, and stir only until all traces of dry ingredients have disappeared, being careful not to over mix. Then pour the brownie batter into the prepared pan.
To make the white chocolate cheesecake topping, first melt the white chocolate using a double boiler or heat safe bowl over a pan of simmering water.
3 ounces (85 grams) white chocolate
In a medium bowl, beat room temperature cream cheese with a hand or stand mixer until creamy. Add the melted white chocolate, sugar, egg, and vanilla extract, and pinch of salt beat until fully combined.
8 ounces (227 grams) cream cheese, ¼ cup granulated sugar, 1 large egg, 1 teaspoon vanilla extract, 1 pinch salt
Pour the cream cheese mixture over the brownie batter in the pan. Use a knife to swirl the two layers together, creating a marbled effect. If you've used binder clips to secure the parchment paper, don't forget to remove your binder clips before baking!
Bake for 35 to 40 minutes, or until the edges are set and a toothpick inserted into the center comes out with a few moist crumbs. Check at about 30 minutes and cover the brownie pan with foil if your cheesecake topping is starting to brown.
Remove the pan from the oven and let the red velvet brownies cool completely in the pan. Use the parchment paper overhang to lift the brownies out of the pan, and slice into squares.