In a saucepan, bring apple cider to a gentle simmer for 15–20 minutes until reduced by half.

Preheat your oven to 350°F while lining a cupcake tin with paper liners.

In a large bowl, combine flour, granulated sugar, brown sugar, baking powder, baking soda, salt, and cinnamon.

In a separate bowl, whisk together the eggs, reduced apple cider, and melted butter.

Gently mix the wet ingredients into the dry ingredients until just combined.

Fill each cupcake liner two-thirds full with batter and bake for about 20 minutes.

Let the cupcakes cool in the tin for 10 minutes, then transfer to a wire rack.

For the buttercream, beat softened butter, then gradually add powdered sugar and mix in heavy cream.

Frost cooled cupcakes with the brown sugar cinnamon buttercream using a piping bag.