Preheat oven to 350 degrees.
Melt 2 teaspoons of butter in the microwave. Pour the melted butter over ¼ cup of breadcrumbs. Stir to combine.
Spread out the buttered breadcrumbs on a baking sheet and place in the hot oven for about 6 to 8 minutes or until the breadcrumbs begin to brown.
Remove the breadcrumbs from the oven. Place the browned breadcrumbs in a small dish.
Cook the pasta shells according to the package directions.
While the pasta is cooking, heat the marinara sauce on the stovetop in a medium-sized pot over medium-low heat.
Make the filling by whisking the egg in a small bowl. Add the ricotta cheese and Italian cheese blend of cheese and stir to combine the cheese mixture.
Place 3 ounces of butter, and 3 ounces of heavy cream in a small pot over medium-high heat.
When the cream begins to bubble, add the parmesan and stir until the cheese has melted. Reduce the heat to low and simmer the mixture.
Stuff 15 shells with ricotta cheese filling.
Pour 1 cup of sauce into the bottom of 3 pasta bowls or pie plates.
Lay 5 stuffed shells on top of the marinara sauce in each of the bowls.
Pour just enough alfredo sauce over the shells to partially cover them.
Place the bowls or pie plates in the oven until the shells are heated through, about 20 minutes.
Garnish with toasted breadcrumbs and chopped fresh parsley.