Preheat a broiler to high, and set a rack close to the heating element.

Add prosciutto to a 10-inch skillet, and cook, stirring occasionally, over medium-low heat until the edges start to crisp. While the prosciutto is cooking, cut the white/pink portion of the ramp from the leaves. Thinly slice the white/pink portion and chop up the leaves. Transfer prosciutto to a plate, increase the heat to medium, add butter to the skillet along with the fiddlehead ferns, sliced white/pink portion of the ramps and a pinch of salt. Cook until tender (3 - 4 minutes), then stir in the chopped ramp greens and cook for 1 minute longer.

Beat together the eggs, Parmesan, crema, a couple of pinches of salt and several turns of black pepper with a fork, then add to the skillet with the ferns and ramps. Add cooked prosciutto. Using a spatula, stir the eggs as if you were scrambling them for 1 minute. Continue to cook the eggs until the sides start to set, but the top still looks wet (about 2 minutes). Run your spatula around the edge of the skillet to create a little space, then drizzle olive oil around the edge. Run your spatula once more around the edge, so the olive oil gets between the sides of the skillet and the eggs. Move the skillet below the broiler, and cook until the top gets golden brown and bubbly (3 to 4 minutes).

While the skillet is still warm, carefully use a spatula to transfer the frittata to a plate or cutting board. Sprinkle with chopped parsley and serve.