Preheat the oven to 350°F and line a baking sheet with parchment paper. Toss the butternut squash with a drizzle of olive oil and a few generous pinches of salt and pepper. Roast until golden brown, 20 to 25 minutes.

Make the cashew cream: Blend together the drained raw cashews, fresh water, garlic, lemon juice, 1/2 teaspoon salt and pepper.

Make the filling: In a medium skillet, heat a drizzle of olive oil over medium heat. Add the spinach in increments, along with a pinch of salt, and sauté until all the spinach is incorporated and wilted. Remove from heat and let cool slightly. Squeeze out any excess liquid and chop. In a medium bowl, combine the the spinach with the crumbled tofu, oregano, lemon zest, red pepper flakes, at least 1/4 teaspoon salt, freshly ground black pepper and 1 cup of cashew cream. Season to taste, adding more salt and pepper as desired.

Bring a large pot of salted water to a boil. Add the shells and cook according to the package directions until al dente. Drain.

Assemble the shells. Spread ¼ cup of the reserved cashew cream on the bottom of an 11x7-inch baking dish. Fill each cooked shell with some of the filling and a few cubes of butternut squash, and place into the baking dish. Drizzle a little olive oil over the shells, cover with foil, and bake for 15 minutes, or until heated through. Remove from the oven and serve with the remaining cashew cream.