Preheat the oven to 325°F (163°C).
Prepare the crust by combining graham cracker crumbs and melted butter in a bowl.
Press the graham cracker mixture firmly into the bottom of a muffin tin lined with paper liners.
In a large mixing bowl, beat the softened cream cheese until smooth, then add granulated sugar and mix until combined.
Add the eggs one at a time, mixing after each addition, then stir in vanilla extract.
Spoon the cream cheese mixture over the graham cracker crusts, filling each cup about two-thirds full.
Bake the cheesecakes in the preheated oven for 15-20 minutes, or until set around the edges but slightly jiggly in the middle.
Remove the cheesecakes from the oven and let them cool to room temperature.
In a separate bowl, combine sliced apples, cinnamon, and brown sugar. Mix until apples are evenly coated.
Top each cooled cheesecake with the cinnamon apple mixture and sprinkle rolled oats and nuts on top.
Return the mini cheesecakes to the oven and bake for an additional 10-15 minutes until the apples are tender.
Let the mini cheesecakes cool completely in the pan, then refrigerate for at least 1 hour before serving.