Compound butter is whipped butter with additional ingredients to enhance the flavor of the food it's spread on. Combinations can be sweet or savory with herbs, spices, sugar, etc. Vegans can substitute coconut oil or Butter Extra Virgin Olive Oil for butter. Compound butter is best paired with biscuits, rolls, grilled meats and vegetables.
To make compound butter, use a fork or hand blender to whip 1 stick of softened unsalted butter. Then, add the sweet or savory ingredients to the butter and blend well. Finally, mold the flavored butter into a log on a piece of parchment paper and chill for 2 hours before slicing.
Source: Michalski, Dara. “6 Incredibly Delicious Compound Butter Recipes.” The Pioneer Woman, The Pioneer Woman, 28 May 2020, www.thepioneerwoman.com/food-cooking/recipes/a88011/how-to-make-compound-butter-recipes/.