Preheat the oven to 450°F. Coat a large rimmed baking sheet with cooking spray.
In a large bowl, toss the cauliflower with oil and salt. Spread the veggies onto the prepared baking sheet; reserve the bowl.
Roast the cauliflower until it's starting to soften and brown on the bottom, about 15 minutes.
Meanwhile, combine Buffalo sauce, butter and lemon juice in the large bowl.
Add the roasted cauliflower and toss to coat with the sauce. Return the cauliflower to the baking sheet and continue roasting until hot, about 5 minutes more.
Remove from the oven and serve with your favorite dipping sauce.