Cauliflower Pizza Bake

Name: Cauliflower Pizza Bake
Ingredients: 1/2 pound (about 2 links) uncooked Italian sausage, removed from casings and cut into 1/2-inch pieces; 2 tablespoons olive oil, divided; 1 large head of cauliflower, trimmed and cut into small, bite-sized florets; 1/2 cup pizza sauce, divided; 1/4 cup finely grated parmesan, plus more for finishing dish; Kosher salt + freshly ground black pepper, to taste; 1/4 cup black olives (I like to use the sliced, canned kind); 1/4 cup slivered or halved sun-dried tomatoes packed in olive oil (drained of oil before using); 2 to 3 ounces pepperoni; 4 ounces fresh mozzarella (sold in rounds or logs), torn into bite-sized pieces; A big handful of fresh basil leaves, torn