Preheat oven to 350 degrees. Place rack in the center of the oven.

Line a 9×13-inch baking pan with foil and grease the foil.

In a food processor or medium bowl, mix together flour, brown sugar, and butter until crumbly. Press the crust into the prepared pan using the back of a measuring cup or the bottom of a loaf pan.

Bake for 10 minutes or until lightly golden.

In a medium bowl or in the bowl of a stand mixer, beat together cream cheese and ½ cup granulated sugar. Mix in eggs and vanilla until smooth. Spread over hot crust.

In a small bowl, mix together 2 tablespoons sugar, cinnamon, and nutmeg. Gently stir sugar mixture together with sliced apples until coated. Evenly layer sugared apples on top of cream cheese layer.

In a small bowl, mix together brown sugar, flour, oats, and softened butter until crumbly. Stir in egg whites until fully combined. Spoon over apples.

Bake for 30-40 minutes or until filling is set and streusel is golden. Cool for 15 minutes, then remove cheesecake bars from the pan using the foil overhang.

Cool completely. Drizzle caramel sauce evenly over the top. Chill in the refrigerator until firm.

Cut into 24 squares for serving.