1. Preheat oven to 325°F. Line a 12-cup muffin pan with paper cupcake liners. Stir graham cracker crumbs, sugar, and melted butter together until the mixture holds together and resembles wet sand. Spoon about 1 1/2 tbsp into each liner and press down firmly with the flat bottom of a shot glass.

2. Combine blueberries and lemon juice in a small saucepan over medium heat. Stir gently as the berries soften and release their juice, about 3 to 5 minutes. Remove from heat and mash with a fork into a thick, slightly chunky sauce. Let the sauce cool to room temperature — do not use it warm.

3. Beat the softened cream cheese and sugar together on medium speed until completely smooth with no lumps, about 2 to 3 minutes. Add the eggs one at a time, mixing on LOW after each addition just until incorporated. Add vanilla and mix briefly. Scrape down the bowl and give one final stir.

4. Spoon half the cheesecake filling evenly over the pressed crusts. Add small dollops (about 1/2 tsp each) of the cooled blueberry sauce across the surface — 2 to 3 dots per cup. Spoon the remaining filling over the blueberry layer. Add a few more small dots of blueberry sauce on top. Drag a toothpick through the surface in gentle S-curves to create the marbled swirl. Make only 1 to 2 passes — too many passes muddy the colors.

5. Bake for 20 to 25 minutes. The edges look set and the centers retain a gentle wobble when you nudge the pan — this is correct. Pull them out while centers still jiggle; they finish setting as they cool.

6. Cool in the pan at room temperature for 15 to 20 minutes. Do not refrigerate while still warm — condensation forms on a warm cheesecake in a cold fridge and affects texture. Once the pan feels cool, cover and refrigerate at least 2 hours before serving.