[header] How to make mint buttercream [title] Whip butter in a standing mixer. [step] Place the butter in a stand mixer that has a paddle attachment. Turn the mixer on medium-high and whip, turning off the mixer every now and then to scape down the sides and ensure that all the butter gets whipped. 
Keep whipping the butter until it's fluffy, around 8 minutes. [substeps] If you don't have a standing mixer, you can mix the frosting by hand, but the texture will be heavier and creamier rather than light and fluffy.