Preheat the oven to 350 degrees F. Add cupcake liners to a muffin pan and set aside.
First make the cupcakes by adding the dry ingredients to a small mixing bowl (flour, baking soda, baking powder, salt, cinnamon and nutmeg). Stir or whisk together.
Melt the butter and add it to a large mixing bowl. Then add the light brown sugar, eggs, and vanilla extract. Whisk to combine. Add the milk and whisk again.
Add the dry ingredients into the wet one third at a time until the batter is combined and smooth.
Fold the peeled, diced apples into the batter gently.
Fill the cupcake liners about ¾ full. Bake for 20-25 minutes or until a toothpick inserted into the middle comes out clean.
When cupcakes are done baking, remove from the oven and place on a wire rack to cool.
Salted Caramel Frosting
After cupcakes have cooled completely, make the frosting. Add the butter to a large mixing bowl. With a hand or electric stand mixer, beat on medium speed for 1 minute.
Begin to add the powdered sugar in thirds until it has all been combined. The mixture will be crumbly. Pause to scrape the bowl and add the heavy cream. Mix again until smooth.
Fold in the caramel sauce and a pinch of salt. Taste the frosting and add any additional caramel or salt based on your preference.
Transfer frosting to a piping bag. Pipe frosting on cooled cupcakes. Drizzle with caramel and enjoy!
Notes
I recommend using Ghirardelli caramel sauce. It is thicker than other sauces and helps to hold the frosting shape really well. You could also make a homemade caramel sauce to use in place of the premade one.How to Store:Store the apple spice cupcakes in an airtight container for a day. If you have any leftovers, store in the refrigerator for up to five days.For longer-term storage, you can freeze the cupcakes for a couple of months, and then thaw them overnight in the refrigerator before serving. I haven't tried freezing them after they've already been frosted, but you might be able to. I'd freeze just the muffins and then make the frosting the day you plan to serve them.If you'd like to make them in advance, I'd recommend making the cupcakes a day ahead and then adding the frosting the day you plan to serve them. Add the drizzle of caramel sauce right before serving.