• Preheat your oven to 350°F (175°C). Line a 9×13 inch baking pan with parchment paper.

Make the crust:

1. In a bowl, mix graham cracker crumbs, melted butter, sugar, and cinnamon.

2. Press the mixture into the bottom of the prepared pan.

3. Bake for 10 minutes, then let cool while preparing the other layers.

Prepare the cheesecake layer:

1. Beat cream cheese and sugar until smooth.

2. Add eggs one at a time, mixing well after each addition.

3. Stir in vanilla extract.

4. Pour over the cooled crust and spread evenly.

Make the apple layer:

1. Toss diced apples with lemon juice, brown sugar, cinnamon, and nutmeg.

2. Spread the apple mixture evenly over the cheesecake layer.

Create the streusel topping:

1. In a bowl, mix flour and brown sugar.

2. Cut in cold butter until the mixture is crumbly.

3. Stir in chopped pecans if using.

4. Sprinkle the streusel over the apple layer.

Bake the bars:

1. Place the pan in the preheated oven and bake for 45-50 minutes, until the streusel is golden and the cheesecake is set.

2. Allow to cool completely at room temperature, then refrigerate for at least 2 hours.

Make the caramel sauce:

1. In a saucepan, combine sugar and water. Heat over medium heat, stirring until sugar dissolves.

2. Increase heat to medium-high and cook without stirring until the mixture turns amber (about 8-10 minutes).

3. Remove from heat and carefully whisk in cream (it will bubble vigorously).

4. Stir in butter and salt until smooth.

5. Let cool slightly.

Serve:

1. Cut the chilled bars into squares.

2. Drizzle with warm caramel sauce just before serving.