Making Salted Caramel Apple Crumble Bars can be a joyful process if you follow these easy steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and grease a 9×9-inch baking dish.
2. Prepare the Crust: In a bowl, combine flour, oats, brown sugar, baking powder, and salt. Stir until evenly mixed.
3. Add Butter: Pour in melted butter and mix until crumbly. Reserve ½ cup of the mixture for the crumble topping.
4. Press into the Dish: Spread the remaining mixture evenly into the bottom of the baking dish, pressing firmly. Bake for 15-20 minutes until lightly golden.
5. Prepare the Apple Filling: In a large bowl, toss diced apples with lemon juice, sugar, cinnamon, and nutmeg. Set aside.
6. Make the Caramel: In a saucepan over medium heat, melt sugar, stirring continuously until it turns a deep amber color. This takes around 5-7 minutes.
7. Add Butter and Cream: Add the chopped butter and stir until melted, then gradually mix in the heavy cream. Remove from heat and stir in sea salt.
8. Assemble the Bars: Once the crust is cooled slightly, spread the apple filling evenly over it. Drizzle the salted caramel on top, ensuring it’s evenly distributed.
9. Add the Crumble Topping: Sprinkle the reserved crumble mixture evenly over the caramel and apples.
10. Bake: Return the baking dish to the oven and bake for an additional 25-30 minutes, or until the topping is golden and the apples are tender.
11. Cool: Remove from the oven and allow the bars to cool in the dish for at least 15-30 minutes before slicing.

With these straightforward steps, you are well on your way to creating a delicious dessert that is sure to captivate your friends and family.