Cook the penne pasta according to package instructions. Drain and set aside.

In a large skillet, heat olive oil over medium heat. Add garlic and sauté until fragrant.

Add shrimp to the skillet, season with salt, pepper, and red pepper flakes (if using), and cook until they turn pink.

Stir in the fresh spinach and cook until wilted.

Add the cooked penne pasta to the skillet and mix well.

Remove from heat and sprinkle shredded cheese on top. Let it melt before serving.