01 - Preheat the oven to 325°F. Line a standard 12-cup muffin tin with paper cupcake liners.
02 - In a mixing bowl, combine the graham cracker crumbs, melted butter, and sugar. Stir until the mixture resembles wet sand and holds together when pressed.
03 - Divide the crumb mixture evenly among the 12 lined muffin cups. Press firmly into the bottom of each cup using the back of a spoon or a small measuring cup to create a compact, even crust layer.
04 - In a separate bowl, beat the softened cream cheese and sugar together using an electric mixer or whisk until completely smooth and creamy, scraping down the sides as needed.
05 - Add the egg and vanilla extract to the cream cheese mixture. Mix on low speed until just combined. Gently fold in the sour cream until evenly incorporated, being careful not to overmix.
06 - Spoon or pipe the cheesecake filling evenly over each prepared crust, filling each cup nearly to the top. Smooth the surface with a small spatula.
07 - Bake for 18 to 20 minutes, or until the centers are set but still have a slight jiggle when gently shaken. Avoid overbaking to maintain a creamy texture.
08 - Remove from the oven and allow the cheesecakes to cool in the muffin tin for 15 minutes. Then transfer them to a wire rack to cool completely to room temperature.
09 - Refrigerate the mini cheesecakes for at least 1 hour to allow them to fully set and develop their flavor.
10 - Top each mini cheesecake with your choice of fresh berries, lemon curd, melted chocolate, caramel sauce, chopped nuts, crushed cookies, or fruit preserves. Serve chilled.