Preheat oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper.
In a food processor, combine Nilla Wafers, graham crackers, and cinnamon; pulse into fine crumbs. Add melted butter and pulse until combined.
Press the mixture evenly into the bottom of the prepared pan. Bake for 8–10 minutes, then let cool slightly.
In a large mixing bowl, beat cream cheese, sour cream, sugar, and vanilla until smooth.
Add the eggs one at a time, mixing on low speed just until combined.
Toss the chopped apples with 2 tablespoons sugar and ½ teaspoon cinnamon, then gently fold them into the cheesecake batter.
Pour the cheesecake mixture over the cooled crust and spread evenly.
In a separate bowl, mix flour, oats, brown sugar, and softened butter with a fork or pastry cutter until crumbly.
Sprinkle the topping evenly over the cheesecake layer.
Bake for 40–45 minutes, or until the center is set and the top is golden brown.
Cool completely, then refrigerate for at least 2 hours before cutting into bars.