Preheat oven to 325°F (163°C) and position rack in center. Line a 24-cup mini muffin pan with foil or paper cupcake liners.
Make the crust by combining cookie crumbs with melted butter until mixture resembles wet sand.
Press 1 tablespoon of crust mixture firmly into the bottom of each liner using a small glass or tart tamper.
Beat cream cheese on medium speed for 2-3 minutes until completely smooth and fluffy. Stop and scrape bowl twice.
Add sugar and sour cream, beating on medium for 1 minute until fully combined. Scrape down bowl again.
Add eggs one at a time on LOW speed, mixing just until incorporated (about 30 seconds each). Do not overmix.
Stir in vanilla and any additional flavorings (cocoa powder, lemon zest, etc.) on low speed until just combined.
Fill each liner ¾ full using a small cookie scoop or spoon, leaving space for expansion.
For swirled variations: Drop small dollops of jam or fruit puree on top, then swirl gently with a toothpick.
Bake for 18-22 minutes until edges are set but centers still jiggle slightly when gently shaken.
Turn off oven and crack door open. Let cheesecakes sit in oven for 10 minutes for gradual cooling.
Remove from oven and cool completely at room temperature for 1 hour.
Refrigerate for at least 2 hours, preferably overnight, before serving.
Add toppings just before serving (fresh fruit, whipped cream, chocolate drizzle, or caramel sauce).