Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper.
Mix flour, milk, garlic powder, onion powder, paprika, salt, and pepper to form a batter.
Toss cauliflower florets in the batter, shaking off excess.
Place coated florets on the baking sheet and bake for 20 minutes, flipping halfway.
Mix buffalo sauce with melted butter.
Remove cauliflower from the oven and toss gently in buffalo sauce.
Return cauliflower to the oven for another 10 minutes until crisp.
Warm slider buns, assemble with slaw, cauliflower, dressing, and toppings.