Preheat your oven to 350°F (175°C) and line a cupcake pan with festive liners.

In a mixing bowl, cream the softened butter and granulated sugar until light and fluffy.

Add the egg whites, vanilla extract, and peppermint extract, mixing until combined.

Sift the cake flour, baking powder, baking soda, and salt together in a separate bowl.

Gradually alternate adding the buttermilk and dry mixture to the butter mixture, mixing until just combined.

Fill cupcake liners about 3/4 full with batter and bake for 17-19 minutes until a toothpick comes out clean.

Allow the cupcakes to cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

For the ganache, combine white chocolate, peppermint chips, and heavy whipping cream in a microwave-safe bowl and heat until melted.

Beat softened butter with a pinch of salt until fluffy, about 5-7 minutes, then mix in melted chocolate and powdered sugar.

Remove the centers from cooled cupcakes and fill with ganache, then frost with buttercream and sprinkle with crushed candy canes.