In the bowl of a stand mixer fitted with the flat beater attachment, beat the butter on medium speed until very light and fluffy.  , Scrape down the sides of the bowl and add 2 cups (227g) of the confectioners’ sugar, maple syrup, maple flavor, milk, and salt.  , Beat the ingredients together on low speed until the sugar is incorporated, then increase the speed to medium; continue to beat until light and fluffy. Adjust with additional confectioners’ sugar or milk as needed to make a light and spreadable frosting. Add maple flavor by the drop for even more flavor, if desired., Use the frosting to finish your dessert of choice: assemble and frost a layer cake or decorate cupcakes. , Storage information: Store maple buttercream frosting in an airtight container in the refrigerator for up to 4 days. Bring to room temperature and re-whip in a mixer before using.