Line the bottom of 12 greased jumbo muffin cups with waxed paper; grease the paper and set aside.

In a small saucepan, melt butter over low heat; stir in brown sugar and corn syrup. Cook and stir over medium heat until sugar is dissolved. Remove from the heat. Spoon 1 tablespoonful into each muffin cup; top each with a pineapple slice and a cherry.

In a large bowl, beat eggs and sugar until thickened and lemon-colored. Beat in the oil, sour cream and vanilla until smooth. Combine the flour, baking powder, baking soda and salt. Add to egg mixture and mix well.

Fill muffin cups two-thirds full. Bake at 350° for 28-32 minutes or until a toothpick inserted near the center comes out clean. Cool for 5 minutes before inverting onto wire racks to cool completely. Garnish with whipped topping if desired.