Preheat oven to 400 degrees F. Grease twelve 2 1/2-inch muffin cups; set aside. In a medium bowl stir together cornmeal, flour, sugar, baking powder, and salt; set aside.
In a medium bowl whisk together half-and half, eggs, and melted butter. Stir in peaches and prosciutto. Add peach mixture to cornmeal mixture; stir just until combined. Divide batter among prepared muffin cups.
Bake for 14 to 15 minutes or just until the edges are golden. (To serve today, omit Steps 4 and 5 and serve warm.)
Let muffins cool completely. Place in an airtight container; cover. Freeze for up to 3 months. Thaw muffins, covered, at room temperature.
Preheat oven to 300 degrees F. Wrap muffins in foil. Bake about 15 minutes or until heated through.