Mash your potatoes as you normally would .
dice up your mozzarella cheese and prosciutto. Melt butter and add minced garlic. Add ingredients to mashed potatoes.
Butter your baking dish. Put your potato mixture in. Lightly brush olive oil on top and sprinkle with grated cheese and Spanish paprika.
At this point you can refrigerate overnight or you can put in a 350 degree oven till lightly browned.