01 - Preheat oven to 325°F. Line a standard 12-cup muffin tin with paper liners.
02 - In a medium bowl, combine 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 about 1 tablespoon per cup. Press firmly into the bottoms using the back of a spoon to form a compact, even layer.
04 - In a large bowl, beat the softened cream cheese with an electric mixer until completely smooth and creamy, scraping down the sides as needed.
05 - Add granulated sugar and beat until fully incorporated. Mix in the egg, vanilla extract, and sour cream, beating just until blended. Avoid overmixing to prevent cracking.
06 - Spoon or pipe the cheesecake filling evenly into the prepared crusts, filling each liner about three-quarters full.
07 - Bake for 18 to 20 minutes, until the centers are nearly set with a slight jiggle. Do not overbake—the filling will continue to set as it cools.
08 - Let the mini cheesecakes cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Refrigerate for at least 1 hour before serving.
09 - Top each mini cheesecake with your choice of fresh berries, chocolate ganache, caramel sauce, whipped cream, or crushed toppings. Serve chilled.