Possible Clues:

• Say butter's gone up; might this do instead?
• Butter-like spread
• Say, butter is on the turn — use this instead?
• Diminutive, fat and married to Homer
• "The Simpsons" mom
• 'The Simpsons' matriarch
• Mrs. Simpson
• Butter substitute is the limit
• Lisa's mother
• She uses blue dye #56