Lightly spray a 9x13 in casserole dish with non stick spray and arrange the halved endive in a single layer. Sprinkle with sugar and roll them around to coat, then season with salt and pepper.
Cover the endives with a sheet of parchment paper, then foil, and bake until tender (35-40 minutes).
Drizzle the heavy cream over the endives and then top with the turkey, bacon, gruyere cheese and then coarse bread crumbs. Scatter the small pieces of butter on top of the dish and bake, uncovered until the top is golden brown and the filling is bubbly (18-20 minutes).