Preheat oven to 450 degrees and bring a pot of of water to boil.
Halve Ciabatta lengthwise.
Peel and halve shallot.
Add pasta to boiling water and cook until al dente (8-10 minutes). Reserve 1/4 cup pasta cooking water when finished.
Combine half the garlic and 1 tsp. olive oil to cut sides of ciabatta.
In a large pan on medium high heat, add 2 tsp. olive oil and shallot to hot pan. Stir occasionally for 2-4 minutes.
Add remaining garlic and cook until aromatic (30-60 seconds).
Add sauce of choice, reserved pasta cooking water, and spinach. Stir occasionally until spinach is wilted (1-3 minutes). Set aside.
Add pasta, asiago, half the parmesan, and 1/4 tsp. salt to pan with sauce and mix thoroughly.
Transfer to casserole dish.
Top with mozzarella, remaining parmesan, and dollops of ricotta.
Cover casserole dish with foil and place on one half of a baking sheet.
Bake for 15 minutes.
Remove from over. Remove foil. Place ciabatta on empty half of baking sheet, cut side up. Bake until cheese is bubbly and ciabatta is toasted (5-7 minutes).