Ingredients:

  • cup (227g) Unsalted Butter
  • ounces (227g) Good Quality Dark Chocolate (60-70% cocoa solids), chopped
  • ½ cups (300g) Granulated Sugar (for brownie)
  • Large Eggs (room temperature)
  • teaspoon Pure Vanilla Extract (for brownie)
  • cup (120g) All-Purpose Flour
  • ½ cup (45g) Unsweetened Cocoa Powder (Dutch-process recommended)
  • ½ teaspoon Fine Sea Salt
  • (8-ounce) package (226g) Full-Fat Cream Cheese, softened
  • ¼ cup (50g) Granulated Sugar (for cheesecake)
  • Large Egg Yolk
  • ½ teaspoon Pure Vanilla Extract (for cheesecake)
  • teaspoon Fresh Lemon Juice

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and line an 8x8 inch pan with parchment paper, leaving an overhang on two sides to act as handles.
  2. Gently melt the butter and chopped dark chocolate together until completely smooth. Remove from heat and whisk in the 1 ½ cups of sugar.
  3. Whisk in the 3 eggs one at a time, followed by the vanilla extract. Sift in the flour, cocoa powder, and salt. Fold gently with a spatula until just combined. Do not overmix.
  4. Prepare the cheesecake layer: Beat the softened cream cheese until smooth. Beat in the ¼ cup sugar, then the egg yolk, vanilla, and lemon juice until silky. Cover and chill briefly.
  5. Press about two-thirds of the brownie batter evenly into the prepared pan, creating the base layer.
  6. Dollop the chilled cheesecake mixture evenly over the brownie layer. Spoon small bits of the remaining brownie batter over the top of the cheesecake.
  7. Use a butter knife or skewer to gently draw lines through the batters to create a marble effect. Avoid over-swirling to maintain definition between the layers.
  8. Bake for 40–45 minutes. The edges should look set, and the cheesecake portion should have minimal jiggle. A toothpick should come out with moist crumbs.
  9. Cool completely on a wire rack (at least 2 hours). For the cleanest slice, chill in the refrigerator for an additional hour before lifting out via the parchment handles and slicing.