I do something very similar. I cook the pasta (spaghetti works best) drain and let it cool a minute. Put it in a large bowl and toss together with a beaten egg, a splash of milk, a bit of parm and salt and pepper. I put that in a 9x13 and top with spaghetti sauce and then all of my pizza toppings. Bake. The pasta stays together and acts like the crust. Whole family loves this one.