Bring a large pot of salted water to a boil and add the rotini. Cook according to package directions until al dente, then drain and set aside. I always use Barilla because it holds its texture perfectly and doesn't get mushy when mixed into the sauce.

Heat the olive oil in a large skillet over medium heat. Add the diced onion and sauté for 3-4 minutes until softened and fragrant. Stir in the minced garlic and cook for 1-2 minutes until aromatic, then add the tomato paste and cook for another 2-3 minutes, stirring frequently to deepen the flavor and eliminate any raw taste. I use Mutti tomato paste because it has a richer, more complex tomato flavor that really elevates the entire sauce.

Pour the vodka into the pan, scraping up any browned bits from the bottom, and let it simmer for 3-4 minutes to cook off the alcohol while the sauce reduces slightly and concentrates in flavor. This step is essential—the vodka adds a subtle sharpness and helps the cream incorporate smoothly into the tomato base.

Reduce the heat to low and stir in the blended cottage cheese mixed with warm water until fully combined and smooth. Add the parmesan cheese, red pepper flakes, salt, pepper, and dried oregano, stirring constantly for about 2 minutes until the cheese melts and the sauce becomes silky and cohesive. If you prefer an ultra-smooth sauce, blend it gently with an immersion blender for 30 seconds, but be careful not to over-blend.

Add the cooked pasta from Step 1, sliced cooked chicken, spinach, and halved tomatoes to the sauce. Gently toss everything together over low heat for 1-2 minutes just until the spinach wilts and the chicken and tomatoes are warmed through. Be gentle when stirring to avoid breaking up the tomatoes and chicken.

Divide the pasta into bowls and drizzle with fresh lemon juice. Garnish generously with fresh parsley, additional parmesan cheese, and a pinch of red pepper flakes for color and heat.