This Peppermint Frosting recipe will be your go-to mint buttercream frosting whenever you need a refreshing minty kick to top your cupcakes, brownies and cookies. It is a Swiss meringue base buttercream so it is velvety smooth and not too sweet!
Add 4 ounce of egg whites and ¾ cup of granulated sugar to a heatproof glass bowl and place it over a pot of boiling water without allowing the bottom of the bowl to touch the water, reduce heat to keep the water simmering and not boiling over. Whisk the mixture constantly until all the sugar dissolves and the mixture reaches 160 degrees Fahrenheit.
Carefully remove the bowl from the pot and wipe the bottom and side dry. Transfer the egg white mixture into your stand mixer bowl and beat with the balloon attachment on medium speed. Stream in ¾ teaspoon of vinegar, and continue beating until stiff peak forms and the meringue is shiny and smooth.
Reduce speed to medium low and slowly add the 10 ounce of room temperature cubed butter, one cube at a time and allow it to incorporate into the meringue. When all the butter is added it will look chunky, like cottage cheese.
Add ¼ teaspoon of vanilla extract and ½ teaspoon of peppermint extract, along with a pinch of kosher salt, increase mixer to high speed and beat for 4-5 mins or up to 30 minutes until the buttercream comes together.
Dip a toothpick into a bottle of green gel food coloring and wipe it on the frosting, beat the frosting until fluffy and the color has incorporated.