Preheat your oven to 350 Degrees F. Line a cupcake tin with cupcake liners.
In a medium mixing bowl, whisk together melted butter, brown sugar, and white sugar. Whisk in the eggs, one at a time, and continue to whisk until combined. Then add the vanilla and apple cider.
In a separate bowl, mix flour, baking soda, salt, and apple pie spice. Whisk dry mixture together, then slowly add the dry mixture to the wet mixture until completely combined.
Using an ice cream scoop, scoop out the batter and spoon it into the prepared muffin tin. Bake for 20 minutes and let the cupcakes cool before frosting.
In a medium saucepan, heat butter, brown sugar, and heavy cream over medium-high heat. Stir until the butter has melted and sugar is dissolved. This is your caramel mixture.
Pour the caramel mixture into the bowl of a stand mixer. Reserve some to drizzle on top after the frosting. Place the mixer bowl into an ice bath and continue to stir until the mixture is room temperature.
Once the mixture is cool, place the mixer bowl in the stand mixer. With the whisk attachment, mix in the powdered sugar one cup at a time. Add the vanilla, make sure to scrape down the sides with a spatula when needed.
Pipe the frosting on top of the cupcakes, then drizzle the leftover caramel on top of the frosting. Sprinkle on some sea salt if desired. Enjoy!