01 - Preheat oven to 325°F. Line a standard 12-cup muffin tin with paper liners.
02 - In a mixing bowl, combine graham cracker crumbs, melted butter, and sugar. Stir until the mixture resembles wet sand and holds together when pinched.
03 - Divide the crumb mixture evenly among the 12 lined muffin cups. Press firmly into the bottom and slightly up the sides using the back of a spoon or a small measuring cup.
04 - In a separate bowl, beat the softened cream cheese and sugar together with an electric mixer until completely smooth and lump-free.
05 - Add the egg and vanilla extract to the cream cheese mixture. Mix on low speed until just incorporated. Gently fold in the sour cream with a spatula until evenly combined. Avoid overmixing.
06 - Spoon or pipe the cheesecake batter evenly over each prepared crust, filling nearly to the top. Smooth the surfaces with a small spatula.
07 - Bake for 18 to 20 minutes, until the edges are set and the centers still have a slight jiggle. Do not overbake.
08 - Remove from the oven and allow the cheesecakes to cool in the pan at room temperature for 15 minutes. Then transfer to a wire rack to cool completely.
09 - Refrigerate the mini cheesecakes for at least 1 hour to fully set before adding toppings and serving.
10 - Top each cheesecake with your choice of fresh berries, lemon curd, melted chocolate, caramel sauce, chopped nuts, crushed cookies, or fruit preserves. Serve chilled.