01 - Preheat the oven to 350°F. Line a 9x9-inch baking pan with parchment paper, leaving overhang for easy removal.
02 - In a large bowl, combine flour, sugar, and salt. Add the cold butter and cut it in using a pastry cutter or your fingers until crumbly. Stir in vanilla extract.
03 - Reserve 1 1/2 cups of the mixture for the topping. Press the remaining dough evenly into the bottom of the prepared pan to form the crust.
04 - Bake the crust for 12 minutes, then remove from oven.
05 - Place apple slices in a bowl and toss with lemon juice. Add sugar, flour, and cinnamon, tossing to coat evenly.
06 - Spread the apple mixture evenly over the hot crust. Drizzle caramel sauce over the apples.
07 - Sprinkle the reserved crumb mixture evenly over the top.
08 - Bake for 28 to 32 minutes or until the topping is light golden brown and apples are tender.
09 - Let cool completely in the pan, then lift out using parchment and cut into bars.