Beat butter, milk, sugar, salt, and pepper into mashed sweet potatoes.
Form 2-inch balls with a center of a marshmallow.
Roll in cornflakes.
Place in greased 9-l/2xl2-3/4-inch baking pan.
Bake in moderate oven of 375 degrees for 25-35 minutes.
May be frozen first, then baked without defrosting for 45 minutes at 375 degrees.