Begin by bringing a large pot of salted water to a rolling boil. Once boiling, add the penne pasta and cook according to the package directions until al dente, usually around 10-12 minutes. Reserve 1/4 cup of the pasta water before draining.

While the pasta is cooking, season the peeled and deveined shrimp with salt, black pepper, and Italian seasoning. In a large skillet over medium heat, melt 2 tablespoons of unsalted butter. Add the shrimp to the skillet and sauté for 4-6 minutes, until they turn pink and opaque. Remove the shrimp from the skillet and set aside.

In the same skillet, add the remaining 2 tablespoons of butter. Add the minced onion and sauté over medium heat for 4-5 minutes until softened and translucent. Stir in the minced garlic and crushed red pepper flakes for about 30 seconds, until fragrant. Then, sprinkle in the all-purpose flour, stirring until it turns lightly golden, about 1-2 minutes.

Slowly whisk in the chicken or vegetable broth to break up any lumps in the flour mixture. Once smooth, add the julienned sun-dried tomatoes and tomato paste, along with the remainder of the seasoning. Lower the heat and let the sauce simmer for about 5 minutes.

Gradually whisk in the heavy whipping cream and whole milk, stirring continuously until the cheese is melted and the sauce is creamy and smooth. Add the fresh spinach, cooking for an additional 2-3 minutes or until wilted.

Carefully toss the cooked penne and reserved pasta water into the creamy sauce. Gently fold in the cooked shrimp and continue to heat everything through for 1-2 minutes.

Once heated through, remove the Marry Me Shrimp Pasta from heat. Transfer to serving plates and garnish generously with grated Parmesan cheese and a sprinkle of minced fresh basil.