Making Apple Crisp Cupcakes is straightforward if you follow these steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and line a 12-cup muffin tin with cupcake liners.

2. Mix Dry Ingredients: In a medium bowl, whisk together flour, baking powder, baking soda, salt, and cinnamon. Set aside.

3. Cream Butter and Sugar: In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

4. Add Eggs and Vanilla: Beat in the eggs one at a time, followed by the vanilla extract, mixing until well combined.

5. Incorporate Dry Ingredients: Gradually add the dry ingredient mixture to the butter mixture, alternating with the buttermilk. Mix until just combined.

6. Fold in Apples: Gently fold in the diced apples until evenly distributed throughout the batter.

7. Prepare Streusel Topping: In a separate bowl, combine oats, brown sugar, flour, cinnamon, and melted butter. Mix until crumbly.

8. Fill Muffin Tin: Spoon the cupcake batter into the prepared muffin tin, filling each liner about two-thirds full.

9. Add Streusel: Evenly distribute the streusel topping over each cupcake.

10. Bake: Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted into the center comes out clean.

11. Cool: Once baked, remove the cupcakes from the oven and allow them to cool in the pan for about 5 minutes. Then transfer them to a wire rack to cool completely.

12. Optional Toppings: Drizzle with caramel sauce or serve with whipped cream for an extra special touch.

These steps will guide you in creating these incredible cupcakes effortlessly, ensuring they are a hit at your next gathering.