01 - Preheat oven to 325°F. Line a 12-cup muffin tin with paper liners.
02 - In a bowl, mix graham cracker crumbs, sugar, and melted butter until combined. Divide mixture evenly among liners and press firmly into the bottoms.
03 - Bake crusts for 5 minutes, then let cool.
04 - In a large bowl, beat cream cheese until smooth. Add sugar and beat well. Add eggs, one at a time, mixing after each. Mix in vanilla and sour cream until fully combined.
05 - Spoon cheesecake filling over cooled crusts, filling each about 3/4 full. Bake for 18-20 minutes, or until centers are just set. Cool completely in pan, then refrigerate at least 2 hours.
06 - In a skillet over medium heat, melt butter. Add diced apples, brown sugar, granulated sugar, cinnamon, nutmeg, lemon juice, and salt. Cook, stirring occasionally, until apples are tender (about 4-6 minutes).
07 - Stir in oats and flour; cook an additional 2-3 minutes until mixture is crumbly and golden. Remove from heat and cool.
08 - Top each chilled mini cheesecake with a generous spoonful of apple crisp mixture. Serve chilled or at room temperature.