01 - Preheat oven to 350°F. Line a 9x9-inch baking pan with parchment paper, leaving overhang for easy removal.
02 - Combine flour, sugar, and salt in a large bowl. Cut in cold butter using a pastry cutter or fingers until crumbly. Stir in vanilla extract.
03 - Reserve 1 1/2 cups of the mixture for topping. Press remaining dough evenly into the bottom of the prepared pan.
04 - Bake crust for 12 minutes, then remove from oven.
05 - Toss apple slices with lemon juice. Add sugar, flour, and cinnamon, coating evenly.
06 - Spread apple mixture evenly over hot crust. Drizzle caramel sauce over apples.
07 - Sprinkle reserved crumb mixture evenly over the top.
08 - Bake for 28-32 minutes until topping is light golden brown and apples are tender.
09 - Cool completely in the pan. Lift out using parchment and cut into 16 bars.