Preheat oven to 350°F (175°C) and place cupcake liners in baking pans.

Cream together unsalted butter and brown sugar on high speed until lighter in color.

Mix in egg whites on medium speed.

Sift flour, baking powder, salt, and cinnamon into the mixture and mix on low speed until just combined.

Mix in sour cream, apple cider, and vanilla extract on low speed.

Fill cupcake liners about ⅔ full. Bake for 18-20 minutes or until a toothpick comes out clean.

Allow the cupcakes to cool for 10 minutes before moving them to a cooling rack.

Optionally place the pan in the freezer for about 30 minutes to accelerate cooling.

Beat room temperature butter on medium high speed for 1-2 minutes until lighter in color.

Mix in vanilla extract, cinnamon, nutmeg, ginger, and salt on low speed.

Slowly add in powdered sugar, half a cup at a time. Add apple cider halfway through.

Mix on low until fully incorporated and desired consistency is reached.

Adjust consistency as needed by adding apple cider or more powdered sugar.

Melt unsalted butter in a large pan over medium heat.

Add diced apples, granulated sugar, lemon juice, cinnamon, nutmeg, ginger, salt, and apple cider. Stir to combine.

Cook for 10-15 minutes until apples soften and mixture thickens.

Remove from heat and let the filling cool. Set aside.

Remove the center from each cooled cupcake.

Fill each cupcake with a generous spoonful of apple filling.

Pipe a mound of spiced buttercream frosting on top of each cupcake.

Chill cupcakes in the fridge for 10 minutes or the freezer for 5 minutes to firm up frosting.

Garnish with an apple chip or apple pie filling on top of the frosting and enjoy!