No. This is a shawarma/rotisserie grill only for roasting meat, chicken, fish, and kebabs. It does NOT support bread or cake baking—no proper baking temperature control or even heating for dough.
A 15-pound turkey is about 6.8kg, which is definitely not enough. The roaster can usually hold a chicken of about 2.5kg. Ribs can also be roasted, but pay attention to the weight and the length and width should not exceed the machine.