Prepare Crumble Topping: In a mixing bowl, whisk together the all-purpose flour, light brown sugar, ground cinnamon, and ground nutmeg until well combined. Cut in the cold unsalted butter using a pastry cutter until it resembles coarse crumbs. Refrigerate while preparing the cupcakes.

Make Apple Filling: Peel, core, and dice the apples. Mix in granulated sugar, lemon juice, ground cinnamon, and a tablespoon of flour. Set aside.

Preheat Oven: Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.

Prepare Batter: In a large bowl, whisk together the flour, baking powder, baking soda, and salt. Cream the butter and light brown sugar until fluffy, then add in the eggs and mix well. Stir in the vanilla extract.

Combine Mixtures: Gradually add the dry ingredients to the creamed butter mixture, alternating with the sour cream. Mix gently until combined.

Assemble Cupcakes: Spoon batter into cupcake liners, filling them two-thirds full. Top with apple filling and sprinkle with crumble topping.

Bake: Place in the oven and bake for 20-25 minutes until a toothpick comes out clean.

Cool and Garnish: Allow cooling for 5 minutes before transferring to a wire rack. Drizzle with caramel sauce and dust with powdered sugar before serving.