Preheat your oven to 350°F (175°C). Line a 9×13 inch baking pan with parchment paper, leaving a little overhang on the sides for easy lifting.

In a medium bowl, combine the flour and brown sugar for the crust. Cut in the cold butter using a pastry blender or your fingers until the mixture looks like coarse crumbs. Press this firmly into the bottom of your prepared pan.

Bake the crust for 15 minutes or until it turns a very light golden brown.

While the crust bakes, beat the softened cream cheese and 1/2 cup of sugar in a large bowl with an electric mixer. Mix on medium speed until smooth. Add the eggs one at a time, then stir in the vanilla extract. Pour this mixture over the warm, pre-baked crust.

In a separate small bowl, toss the diced apples with 2 tablespoons of sugar, cinnamon, and nutmeg. Spread the apple mixture evenly over the cream cheese layer.

To make the streusel, combine the brown sugar, flour, and oats in a bowl. Cut in the cold butter until the mixture is crumbly. Sprinkle this topping generously over the apples.

Bake the bars for 40 to 45 minutes. The filling should be set and the streusel topping should be golden brown.

Remove the pan from the oven and let it cool to room temperature. Once cool, place the pan in the refrigerator for at least 3 hours or overnight.

Before serving, lift the bars out of the pan using the parchment paper. Drizzle the caramel sauce over the top and cut into squares.