Why are my homemade Manicotti Shells doughy? I handmade fresh pasta sheets for my manicotti recipe. 

Without cooking the pasta sheets in boiling water I stuffed the sheets (shells) with the cheese filling, topped with tomato sauce and cooked for about 60 minutes. 

The pasta was doughy and soft, almost undercooked. 

Do you advise cooking the fresh pasta sheets first? Why was it undercooked?
I would guess that they were too thick. They need to be so thin they're almost translucent, especially if you roll them with overlap. Fresh pasta feels doughy easily if it's too thick.