In a small bowl, combine the granulated sugar and ground cinnamon.
Whisk until evenly blended, then set the cinnamon sugar mixture aside.
Transfer the apple pie filling to a cutting board.
Using a large knife, coarsely chop the apples into smaller pieces.
Set the chopped apple pie filling aside.
Place a skillet or pan over medium heat.
Add 1/2 tbsp of butter to the pan and allow it to melt.
Place one tortilla in the pan.
Cook the tortilla for approximately 1 minute, or until it begins to crisp lightly.
Remove the crisped tortilla from the pan and set it aside. This tortilla will be used as the top layer of the quesadilla.
Add another 1/2 tbsp of butter to the pan and allow it to melt.
Place a second tortilla in the pan.
Drizzle 1 tbsp of caramel sauce over the tortilla.
Spread approximately 1 cup of chopped apple pie filling evenly over the caramel sauce.
Drizzle an additional 1 tbsp of caramel sauce over the apple pie filling.
Place the reserved crisped tortilla on top of the filling.
Allow the quesadilla to heat through until the bottom tortilla is lightly crisp and golden.
Carefully flip the quesadilla if needed to warm and crisp both sides evenly.
Remove the quesadilla from the pan.
Sprinkle the top with the prepared cinnamon sugar mixture.
Transfer the quesadilla to a cooling rack.
Repeat the process with the remaining tortillas, butter, caramel sauce, and apple pie filling.
Allow the quesadillas to cool slightly before slicing.
Cut each quesadilla into quarters.
Serve with additional caramel sauce, vanilla ice cream, or whipped cream if desired.