Peel and chop the sweet potatoes into 1 inch cubes. Place on a baking pan with some olive oil and roast at 375°F for ~25 minutes. Once done, preheat the oven to 400°F.
Cook the shells according to directions on the box. Place all ingredients for the cashew cream into a blender and blend until completely smooth. Add water as needed.
In a bowl, mix the ingredients for the tofu ricotta. Pour the cashew cream into the bowl and mix it all together.
Fill each shell with the filling (check out the easiest way to do this above!) and top each with a few cubes of baked sweet potato.
Spread 1/4 of the marinara sauce on the bottom of a large glass baking dish. Place the shells on the dish.
Drizzle the rest of the marinara sauce over them all.
Cover with foil and bake for ~30 minutes. Enjoy!