Preheat the oven to 350F. Butter a 13x9-inch- or 3-quart baking dish or spray with nonstick cooking spray and set aside.

In a medium bowl, cover the sun- dried tomatoes with the boiling water and set aside to soften.

Heat the olive oil in a large skillet over medium- high heat. Add the sausage and cook, breaking up the sausage with the back of a spoon, until it is just browned, about 5 minutes. Add the onion and continue cooking for 5 minutes, stirring occasionally. Remove the pan from the heat. If the sausage is especially greasy, drain off the heat.

In a large mixing bowl, whisk together the eggs, milk, cream, salt, Italian seasoning, and pepper. Add the bread cubes and toss to coat the bread completely. Let stand for 5 minutes, tossing occasionally to help the bread absorb the liquid evenly.

Drain the sun- dried tomatoes throughly and add them to the bread mixture. Add the olives, cooked sausage and onion, and mozzarella. Pour the mixture into the prepared baking dish, gently pressing down with your hands to evenly distribute the mixture. Cover the dish loosely with foil and bake for 35 minutes. Remove the foil and continue baking until the top is golden brown and the center is set, about 30 more minutes.

Let cool for 15 minutes and top with the fresh basil before serving. Refrigerate any leftovers for up to 3 days.