Cook the Pasta Shells: Bring a large pot of salted water to a rolling boil. Add the jumbo pasta shells and cook until al dente, following package instructions, usually about 10-12 minutes. Once cooked, drain the pasta and carefully set the shells aside on a baking sheet to prevent sticking while you prepare the filling and sauce.

Sauté Shallots and Garlic: In a large skillet, heat one tablespoon of olive oil over medium heat. Add the minced shallot and cook for about 3-4 minutes until softened and translucent. Then, stir in the minced garlic and red pepper flakes, cooking for an additional minute until fragrant.

Create the Sauce Base: Add the tomato paste and vodka to the skillet, stirring continuously for about 2 minutes. Then, pour in the can of whole peeled tomatoes along with their juice. Use a wooden spoon to break up the tomatoes and mix in fresh basil leaves along with salt and pepper. Allow the sauce to simmer for 15 minutes while you prepare the filling.

Finish the Sauce: Once the sauce has simmered, remove the basil leaves and stir in the half and half along with a tablespoon of butter. Let the sauce continue to simmer for an additional 5 minutes to achieve a creamy consistency.

Sauté the Spinach: In another skillet, heat a splash of oil over medium heat and add the fresh spinach along with minced garlic. Sauté until the spinach is wilted, about 3-4 minutes. Remove from heat and let it cool slightly before combining it with ricotta cheese, shredded mozzarella, grated Parmesan, salt, and pepper in a mixing bowl.

Assemble the Dish: Preheat your oven to 375°F (190°C). Spread a layer of the prepared basil vodka sauce in the bottom of a baking dish. Carefully fill each cooked pasta shell with the creamy spinach ricotta mixture, placing them seam-side up in the baking dish. Top with the remaining sauce.

Bake the Stuffed Shells: Cover the baking dish with foil and place it in the preheated oven, baking for about 25 minutes. After this time, remove the foil and bake for an additional 10-15 minutes until the top is bubbly and golden.

Serve and Garnish: Once baked, let the dish cool for a few minutes. Just before serving, sprinkle with additional grated Parmesan cheese and minced fresh basil.