Place an oven rack in the center of the oven. Preheat the oven to 350 degrees F. Butter an 8 by 8-inch casserole dish. Set aside.
In the bowl of a food processor, blend the bread until it forms into crumbs.
In a large non-stick skillet, heat the butter over medium heat. Add the bread crumbs and cook, stirring constantly until all the butter has been absorbed and the bread crumbs are toasted, about 1 to 2 minutes.
In a medium bowl, whisk together the cream and flour. Add the capers, bacon and 1/2 cup of the Gruyere. Season with salt and pepper, to taste.
Bring a medium saucepan of water to a boil over high heat. Add the cauliflower and cook for 2 minutes. Drain the cauliflower and toss with the cream mixture. Pour the cauliflower mixture into the prepared baking dish. Sprinkle with the bread crumbs and remaining 1/2 cup of cheese.
Drizzle with olive oil and bake for 35 to 40 minutes until the cheese has melted and the top is golden brown.