Preheat oven to 325°F (160°C). Line a muffin tin with 12 paper liners.
Mix graham cracker crumbs and melted butter. Press about 1 tablespoon of the mixture into the bottom of each muffin liner. Bake for 5 minutes, then let cool.
In a mixing bowl, beat cream cheese and sugar until smooth. Add egg, Greek yogurt, and vanilla; mix until well combined.
Divide cheesecake batter evenly among the muffin cups over the crusts.
Add a small spoonful of blueberry jam on top of each and use a toothpick to gently swirl it into the batter.
Bake for 15–18 minutes until centers are set but slightly jiggly. Let cool, then chill in the fridge for at least 1 hour.
Notes
Store chilled for up to 4 days. You can use raspberry or strawberry jam for a different swirl flavor!