Grease an 8-inch springform pan on the base and sides and then line the base with parchment paper (optional).
In a food processor, pulse the oatmeal cookies until finely ground. Combine with oatmeal flakes and melted butter.
Firmly press the crumb mixture into the bottom of the prepared pan.
Bake in a hot oven for 12-15 minutes. Allow it to cool.
Filling
In a mixing bowl, beat the cream cheese with an electric mixer until smooth and creamy. Add cornstarch, vanilla, cinnamon, and sugars and mix until well combined.
Pour the cream cheese mixture evenly over the cooled crust.
Top with apple slices (any way you want).
Topping
In a small bowl, combine flour, sugar, and cinnamon. Using a pastry blender or fork, cut in the butter until fine crumbs form. Sprinkle evenly over the apples.
Place the springform pan on a baking sheet (prevents any leaks to the bottom of your oven). Bake in a 350 F preheated oven, about 40-50 minutes.
Allow it to cool, then refrigerate for at least 4 hours before serving.
Loosen the sides of the cheesecake with a knife, and then carefully remove the sides of the pan.
Notes
Drizzle apple slices with lemon juice to prevent from browning.
Serve this cake on a nice cake stand for that wow effect, although a dinner plate is nice too.
Please keep in mind that nutritional information is a rough estimate and can vary significantly based on products used.