Preheat your oven to 350°F (175°C) and line an 8x8-inch baking pan with parchment paper, leaving some overhang for easy removal later.

In a mixing bowl, combine the flour, softened butter, granulated sugar, vanilla extract, and salt. Mix until the mixture resembles coarse crumbs. Press this mixture into the bottom of the prepared baking pan to form an even crust.

In a separate bowl, toss the diced apples with cinnamon, brown sugar, and lemon juice. Spread the apple mixture evenly over the crust in the baking pan.

In another bowl, beat the softened cream cheese until smooth. Gradually add powdered sugar and mix until well combined. Add vanilla extract and the egg, mixing until fully incorporated.

Pour the cream cheese mixture over the apples, spreading it evenly. Drizzle caramel sauce over the top of the cream cheese layer.

Bake in the preheated oven for 35-40 minutes or until the cheesecake layer is set and the edges are lightly golden. Allow to cool in the pan for at least 30 minutes before transferring to the refrigerator to chill for at least 2 hours.

Once chilled, lift the bars out of the pan using the parchment overhang and cut into squares. Drizzle with additional caramel sauce and sprinkle with chopped nuts if desired before serving.