Add whipping cream to Twister jar, and place lid on jar. Select Speed 2, and run full cycle. While blending, turn Twister lid counterclockwise. Add remaining ingredients, place lid on jar, and select Speed 2. Run full cycle or until liquid separates from solid butter ball. While blending, turn Twister lid counterclockwise.
Strain liquid from butter ball. Place ball in airtight container, or wrap tightly in plastic. Butter will keep for 3 days in refrigerator.
For lime-cilantro butter, use lime juice in place of lemon juice and cilantro in place of rosemary. For onion or garlic butter, use fresh chives in place of rosemary and add ¼ teaspoon garlic powder or onion powder.