01 -
Preheat oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper.
02 -
In a saucepan, melt butter and chocolate over low heat, stirring until smooth. Remove from heat. Whisk in sugars, then eggs and vanilla. Stir in flour and salt until just combined. Pour into prepared pan.
03 -
In a medium bowl, beat cream cheese, sugar, egg yolk, and vanilla until smooth. Divide cheesecake mixture into three portions. Tint one red and one blue with gel coloring, leaving the third plain.
04 -
Drop spoonfuls of the red, white, and blue cheesecake over brownie batter. Swirl gently with a toothpick or skewer to create a marbled effect.
05 -
Bake for 30–35 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
06 -
Cool completely in the pan before slicing.