01 - Beat the softened butter using a hand mixer or stand mixer until light and creamy, about 1 minute.
02 - Gradually add sifted powdered sugar on low speed to prevent a sugar cloud, mixing until fully combined.
03 - Blend in ground ginger, cinnamon, nutmeg, cloves, and optional salt until uniformly distributed.
04 - Pour in vanilla extract and molasses if using, mixing to combine.
05 - Add milk one tablespoon at a time, mixing on medium speed until desired smoothness for spreading or stiffness for piping is achieved.
06 - Use immediately to frost cooled gingerbread cookies, cakes, or cupcakes.