Fit pastry bag with desired decorating tip. Spoon enough frosting into prepared bag to fill about halfway. Use to pipe frosting onto cupcakes, refilling bag with remaining frosting if necessary. Or if you don't have a pastry bag, you can use a resealable plastic bag instead. Spoon frosting into bag, then cut piece off one bottom corner of bag before using to frost cupcakes.
How to Store
How to Easily Fill Muffin Cups
Filling muffin cups with muffin or cupcake batter can be a messy task. Make it neat and easy by using an ice cream scoop to fill the cups. This also ensures that an equal amount of batter is portioned into each muffin cup.