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.
[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.