01 - Preheat oven to 325°F. Line a standard 12-cup muffin tin with paper liners and set aside.
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 create a compact, even layer.
04 - In a large bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Add granulated sugar and continue beating until fully incorporated and free of lumps.
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 excess air and 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 almost set with a slight jiggle. Remove promptly — do not overbake, as the filling will continue to set while cooling.
08 - Allow the mini cheesecakes to cool in the muffin tin for 10 minutes. Transfer to a wire rack to cool completely, then 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 cookies and nuts.