Beat all ingredients with an electric mixer at high speed until smooth.
Butter mixture can be used while still soft; or it can be rolled into a cylinder in parchment paper or plastic wrap and refrigerated or frozen, then sliced into teaspoon-sized rounds.
Allow 2 or 3 teaspoons per serving.
Flavored butter can be stored a couple days in the refrigerator or it can be frozen for several weeks. Learn more about how to make compound butter.