Preheat the oven to 300F and line the bottom of an 8x8-inch baking pan with parchment. Leave the edges of the parchment over the sides for easy removal. Alternatively, you can also use a high quality, nonstick aluminum foil.

In a medium bowl, add the melted butter, granulated sugar, vanilla extract, salt, and stir to combine.

Fold in the flour and stir until combined.

Press the crust mixture into the bottom of the lined baking pan and bake for 15 minutes at 300F. Set a timer so you don't forget and set aside to cool if you are speedy with steps 5 and 6! Tip- Prepare the filling while the crust is baking to save time.

To a large bowl, add the sliced apples, flour, granulated sugar, cinnamon, optional ginger, nutmeg and stir to combine and coat evenly; set aside.

To a medium bowl, add the flour, brown sugar, and butter. With a fork, gently cut the butter into the dry mixture until a crumbly texture is achieved. Tip - I find that softened butter rather than cold butter (more typical) is easier to work and yields the same result in this recipe.

Turn the oven up to 350F degrees. On top of the warm crust, evenly spread the apple filling mixture with a rubber spatula.

Evenly sprinkle the crumble topping mixture on top and bake for 30 to 35 minutes at 350F, or until the crumble is golden brown. Baking Tips- Always watch your items and not the time on the clock when determining doneness. When the top is lighlty golden browned and set, and you can see a bit of bubbling from the apple filling beneathe, they're likley done. Rotate pan once halfway through this round of baking to ensure a more evenly golden browned top.

Remove pan from the oven and allow bars to cool on a wire rack for at least 2 hours, or overnight. If desired, after cooling at room temp for 20 minutes, you can chill in the fridge 2 hours if you like chilled desserts. Do not cover (either on the counter or in the fridge) or the top won't stay crispy/crumbly and will soften.

When ready to serve, evenly drizzle the caramel sauce over the top as desired, slice, and serve.