Preheat the oven to 325 degrees F.
Line 12 muffin cups with liners. Spray the liners with non-stick spray.
Combine the graham crumbs, melted butter, and brown sugar in a medium sized bowl. Spoon a little of this mixture into each of the muffin cup liners. Press it evenly into the bottom of the cups.
Use a stand mixer (or hand mixer) to cream the cream cheese. Then add the greek yogurt, egg, caramel sauce, brown sugar, vanilla, and cinnamon. Mix this until smooth.
Spoon the cheesecake mixture evenly over the crusts in each of the muffin cups.
Peel, core, and dice the apples. Measure the brown sugar and cinnamon into a medium size bowl and combine them well. Then add the diced apples and stir to coat them well. Set this aside.
In a separate, large bowl, whisk together the flour, brown sugar, rolled oats, and cinnamon. Then use a pastry cutter to cut in the softened butter until the mixture is crumbly.
Spoon a little of the apple mixture into each muffin cup. Then spoon on a little of the topping.
Bake for 30 minutes.
Chill for at least 2 hours. Garnish with whipped cream if desired.