👨‍🍳 Bring a large pot of well-salted water to a boil. Add the pasta and cook according to package directions until al dente.

👨‍🍳 While the pasta cooks, heat olive oil in a large skillet over medium heat. Add minced garlic and sauté for about 30 seconds until fragrant.

👨‍🍳 Add the fresh spinach to the skillet and cook until wilted, about 2 to 3 minutes.

👨‍🍳 Once the spinach is soft, pour in the milk or half-and-half, stirring to combine. Bring the mixture to a gentle simmer and then reduce the heat to low.

👨‍🍳 Gradually add the grated Parmesan cheese, stirring constantly until fully melted and smooth.

👨‍🍳 If using, stir in the cream cheese or Greek yogurt for extra richness and stability.

👨‍🍳 Season the sauce with salt, black pepper, and red pepper flakes if using.

👨‍🍳 Once the pasta is done, reserve about 1/2 cup of the pasta water and drain the rest.

👨‍🍳 Add the cooked pasta directly into the sauce and toss to coat.

👨‍🍳 If the sauce is too thick, add the reserved pasta water gradually until the desired consistency is reached.

👨‍🍳 Taste and adjust seasonings as needed, then serve immediately.