Spinach Artichoke Pasta

1 12-oz box pasta
1 tsp butter
2 cloves garlic, minced
1 8 oz package reduced fat cream cheese
1/2 cup milk
1/2 cup reduced fat sour cream
1/2 lemon, juiced
1/2 tsp salt
1/4 tsp red pepper flakes
1 14 oz can artichoke hearts (packed in water), drained and chopped
10 oz chopped, frozen spinach, thawed, with as much excess water squeezed out as possible
1/2 cup parmesan cheese, shredded
additional Parmesan for serving

Cook pasta according to package directions. In a medium saucepan over medium heat, melt butter and add garlic. Cook until fragrant, about 30 seconds. Add cream cheese and stir until melted. Slowly stir in milk, then add sour cream, lemon juice, salt and red pepper flakes. Stir in artichoke hearts, spinach, and parmesan cheese. Drain pasta and add to artichoke mix. Toss and season to taste with salt and additional lemon juice as needed. Serve with additional shredded Parmesan.