✅ Step 1: Prepare the Blackberry Compote

In a small saucepan over medium heat, combine blackberries, sugar, and lemon juice. Stir until the berries break down and release their juices. Simmer for 8-10 minutes until the mixture thickens. Strain through a fine mesh sieve for a seedless puree (optional). Let cool.

✅ Step 2: Make the Brownie Batter

Melt the butter and mix it with sugar, eggs, and vanilla extract. Stir in cocoa powder, flour, and salt until combined. Pour the batter into the lined baking pan, reserving 1/4 cup for swirling.

✅ Step 3: Make the Cheesecake Layer

In a medium bowl, beat cream cheese with sugar, egg yolk, and vanilla until smooth. Pour over the brownie batter in an even layer.

✅ Step 4: Add Blackberry Swirl

Drop spoonfuls of the blackberry compote over the cheesecake layer. Add small dollops of the reserved brownie batter as well. Use a skewer or toothpick to gently swirl the layers together into a marbled pattern.

✅ Step 5: Bake

Bake in a preheated 350°F (175°C) oven for 35-40 minutes or until the center is just set. Cool completely before slicing.