Whipped cream and/or shaved chocolate, for topping (optional)
Blend the milk, peanut butter and half of the ice cream in a blender until smooth. Transfer to a liquid measuring cup and place in the freezer.
Rinse out the blender and blend the remaining ice cream, the grape juice and jelly until smooth. Pour equal parts of the peanut butter and jelly mixtures into chilled glasses. Top with whipped cream and/or shaved chocolate, if desired.