Cook the Pasta: Bring a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente, about 8-10 minutes. Reserve ¼ cup of pasta water before draining, then set the pasta aside.

Cook the Chicken: Heat olive oil in a skillet over medium-high heat. Season the chicken with salt and pepper, add to the skillet, and cook until golden brown and cooked through, about 5-7 minutes per side. Remove from skillet and let rest before slicing.

Sauté Aromatics: In the same skillet, reduce heat to medium and melt the butter. Add diced shallot and minced garlic, cooking until translucent and fragrant, about 3-5 minutes.

Build the Sauce: Stir in red pepper flakes and tomato paste, cooking for an additional 3-5 minutes. Add vodka and let simmer for about 2 minutes.

Creamify the Sauce: Lower heat to medium-low and stir in the heavy cream and Parmesan cheese until well combined and creamy.

Combine Ingredients: Return the cooked pasta to the skillet along with baby spinach and basil. Mix in the reserved pasta water until everything is well coated and the spinach wilts slightly.

Serve and Garnish: Serve immediately garnished with additional Parmesan and fresh basil.