If you’ve ever been to a church potluck in the Deep South or Midwest, you’re undoubtedly familiar with ambrosia. If you’re unacquainted, it’s a syrupy sweet, quivering mass of canned fruit, non-dairy whipped topping, coconut, and miniature marshmallows, a sort of dessert that teeters toward fruit salad (or vice versa). It often appears at Thanksgiving…