Preheat your oven to 350°F (175°C). Line a cupcake pan with paper liners to prevent sticking and make for easy removal.

In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, and salt. This ensures that the dry ingredients are evenly distributed.

In another bowl, cream the softened butter using an electric mixer on medium speed until light and fluffy, about 2-3 minutes. This incorporates air into the butter, giving the cupcakes a light texture.

Add the eggs, buttermilk, and vanilla extract to the butter, mixing until well combined. Scrape down the sides of the bowl to ensure everything is mixed evenly.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Overmixing can lead to dense cupcakes.

Fold in the diced apples, cinnamon, and nutmeg gently with a spatula until evenly distributed.

Spoon the batter into the prepared cupcake liners, filling each about ⅔ full to allow room for rising.

Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean. This ensures that the cupcakes are fully cooked.

Once baked, remove from the oven and let the cupcakes cool in the pan for 5 minutes before transferring them to a cooling rack to cool completely.

In a large mixing bowl, beat the softened butter with an electric mixer on medium speed until creamy.

Gradually add the sifted powdered sugar, mixing on low speed until incorporated. This prevents a sugar cloud from forming.

Add the heavy cream, vanilla extract, and cinnamon. Beat on medium-high speed for about 2-3 minutes until the frosting is light and fluffy.

Once the cupcakes are completely cool, use a piping bag fitted with a star tip to frost each cupcake generously with the cinnamon buttercream.

If desired, drizzle caramel sauce over the frosted cupcakes and sprinkle with toasted pecans for added flavor and texture.