01 - Preheat oven to 325°F. Line a standard 12-cup muffin tin with paper liners.
02 - In a medium bowl, combine the graham cracker crumbs, melted butter, and sugar. Stir until the crumbs are evenly moistened and resemble wet sand.
03 - Divide the crumb mixture evenly among the 12 muffin cups, using roughly 1 tablespoon per cup. Press firmly into the bottom of each liner using the back of a spoon or a small flat-bottomed glass.
04 - In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Add the sugar and continue beating until fully incorporated.
05 - Add the egg, vanilla extract, and sour cream to the cream cheese mixture. Beat on low speed until just blended — avoid overmixing to prevent cracks.
06 - Spoon or pipe the cheesecake batter evenly into the prepared crusts, filling each liner about three-quarters full.
07 - Bake for 18 to 20 minutes, until the centers are almost set with a slight jiggle. Do not overbake — the cheesecakes will continue to set as they cool.
08 - Let the cheesecakes cool in the muffin tin for 10 minutes, then transfer to a wire rack to cool completely. Refrigerate for at least 1 hour before serving.
09 - Before serving, top each mini cheesecake with your choice of fresh berries, chocolate ganache, caramel sauce, whipped cream, or crushed toppings.