Bring a large pot of salted water to a boil and cook pasta according to package instructions. Reserve 1 cup of pasta water before draining.

In a large skillet, heat olive oil over medium heat. Add minced garlic and sauté for 1-2 minutes until fragrant.

Add the fresh spinach to the skillet and cook for 2-3 minutes until wilted. Remove from heat.

In a bowl, mix ricotta cheese with lemon zest, lemon juice, salt, and black pepper. Add a few tablespoons of the reserved pasta water to loosen the mixture.

Return the drained pasta to the pot or skillet. Add the ricotta mixture and toss to coat evenly. Add more pasta water if needed to create a creamy sauce.

Stir in the sautéed spinach and mix well. Taste and adjust seasoning with salt, pepper, or lemon juice if needed.

Serve warm, topped with Parmesan cheese and red pepper flakes if desired.