Preheat oven to 450°F and line a baking sheet with foil. On top of the foil-covered baking sheet, place an oven-safe baking rack, and spray with cooking spray.
In a medium-sized bowl, combine 3/4 cup flour, 1 cup milk, 1/2 teaspoon each of black pepper and garlic powder, and 1 teaspoon chili powder. Whisk until lumps are gone and batter has thickened. Add the cauliflower florets into the bowl with the batter, and toss to coat the cauliflower thoroughly.
Place the coated cauliflower in one layer on the baking rack on the pan. Leave enough space between each cauliflower floret so none is touching. Bake in the preheated oven for 20 minutes or until the cauliflower starts to brown.
While the cauliflower is baking, mix together the Maple Chipotle Barbecue Sauce. In a medium bowl add 2/3 cup of your favorite barbecue sauce, 1/3 cup maple syrup (the amount may need to be adjusted depending on the sweetness of the barbecue sauce), and 1 - 2 chipotle chilies (depending on how spicy you like it), and 1 tablespoon adobo sauce.
When the cauliflower is ready, remove it from the oven and toss it with the Maple Chipotle Barbecue sauce so it is thoroughly coated.
Spray the baking rack with cooking spray again and place the Maple Chipotle Barbecue Cauliflower on the baking rack, and place back in the oven. Bake for 10 more minutes, or until browned to your liking. Remove from oven and carefully transfer the hot Maple Chipotle Barbecue Cauliflower to a serving dish. Serve with your favorite dipping sauce, such as ranch dressing. I served it with a Salsa Ranch Dressing!