Preheat oven to 450 degrees F. Place the pizza shell on a cookie sheet. Scatter spinach all over crust. Drizzle with oil. Evenly distribute prosciutto, Parmesan and garlic on top of spinach. Crack eggs onto pizza, roughly positioning 1 yolk on each pizza quarter. Bake for 12-15 minutes, until spinach is wilted and egg whites are just fully cooked. Cut into 4 large slices.