Prepare 16 white cupcakes according to package directions (or use your favorite homemade white cake recipe).
Transfer cupcakes to a cooling rack to finish cooling.
While cupcakes are cooling, prepare frosting.
Using a stand mixer with the whisk attachment, mix together butter, salt, lemon juice, peppermint extract, and vanilla extract until combined.
Add in 2 cups of powdered sugar along with 3 tablespoons heavy cream. Mix.
Pour in remaining powdered sugar and mix. Once combined, turn the stand mixer on high and beat for 5 minutes. The frosting should be very light and fluffy.
Add frosting into a piping bag with a Wilton 1M frosting tip and frost cupcakes.
Sprinkle on the crushed peppermint candies and top with a mini marshmallow.
Notes
The calories shown are based on the recipe making 16 cupcakes, with 1 serving being frosted cupcake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**