Creating amazing Apple Spice Cupcakes with Spiced Buttercream Frosting is simple. Follow these steps for the best results:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
2. Mix Dry Ingredients: In a large mixing bowl, whisk together the flour, granulated sugar, brown sugar, baking powder, baking soda, salt, cinnamon, and nutmeg until well combined.
3. Combine Wet Ingredients: In another bowl, mix the vegetable oil, eggs, and vanilla extract. Whisk until fully blended.
4. Add Apples: Stir the grated apples into the wet mixture, ensuring they are evenly distributed.
5. Combine Mixtures: Gradually add the wet ingredients to the dry ingredients, stirring gently until just combined. Be careful not to overmix.
6. Add Walnuts: If using, fold in the chopped walnuts for added texture and flavor.
7. Fill Cupcake Liners: Use a scoop or spoon to fill each cupcake liner about two-thirds full with the batter.
8. Bake: Place the muffin tin in the preheated oven and bake for 20-25 minutes or until a toothpick inserted in the center comes out clean.
9. Cool: Remove the cupcakes from the oven and allow them to cool in the tin for about 10 minutes. Then, transfer them to a wire rack to cool completely.
10. Prepare the Frosting: While the cupcakes cool, make the spiced buttercream frosting. In a large bowl, beat the softened butter until creamy. Gradually add the powdered sugar, mixing well. Add the vanilla extract, cinnamon, nutmeg, and enough heavy cream to reach your desired consistency.
11. Frost the Cupcakes: Once the cupcakes are completely cool, use a piping bag or a knife to frost each cupcake with the spiced buttercream frosting.
12. Decorate (Optional): Add a sprinkle of cinnamon or a few chopped walnuts on top of the frosting for a finishing touch.