01 - Preheat oven to 325°F. Line a standard 12-cup muffin tin with paper cupcake liners and set aside.
02 - In a medium mixing bowl, combine graham cracker crumbs, melted butter, and sugar. Stir until the mixture resembles wet sand and all crumbs are evenly coated.
03 - Divide the crumb mixture evenly among the 12 lined muffin cups. Using the back of a spoon or a small measuring cup, press the crumbs firmly into the bottom of each liner to form a compact, even crust layer.
04 - In a large mixing bowl, beat the softened cream cheese and granulated sugar together using an electric mixer on medium speed until the mixture is completely smooth and creamy, approximately 2 minutes.
05 - Add the egg and vanilla extract to the cream cheese mixture. Beat on low speed until just incorporated. Gently fold in the sour cream with a spatula, being careful not to overmix.
06 - Spoon or pipe the cheesecake filling evenly over each prepared crust, filling each liner nearly to the top. Smooth the surface with a small spatula or the back of a spoon.
07 - Bake on the center rack for 18 to 20 minutes, or until the edges are set and the centers still have a slight jiggle when gently shaken. Avoid overbaking to prevent cracking.
08 - Remove from the oven and allow the cheesecakes to cool in the muffin tin at room temperature for 15 minutes. This gradual cooling helps prevent sinking and cracking.
09 - Transfer the mini cheesecakes to a wire rack to cool completely. Once at room temperature, place them in the refrigerator and chill for at least 1 hour to fully set the filling.
10 - Top each chilled mini cheesecake with your choice of fresh berries, lemon curd, melted chocolate, caramel sauce, chopped nuts, crushed cookies, or fruit preserves. Serve immediately.