Sweet Potato Muffins, the former Renaissance Jamaica Grande

1 cup sugar
1 cup butter
6 eggs
1 teaspoon vanilla
2 cups milk
1 1/2 cups flour
2 tablespoons baking powder
1 pound cooked sweet potatoes, mashed

Cream butter and sugar together. Add eggs, vanilla, milk, flour, baking powder, and sweet potatoes. Mix thoroughly to ensure even mixture of ingredients. Drop batter in greased muffin tins. Bake at 350 degrees for 30 minutes or until muffins are springy and golden brown. Yields 15 to 20 muffins.