Preheat the oven to 425°F (220°C).
Cut the cauliflower into bite-sized florets.
In a bowl, whisk together olive oil, soy sauce, smoked paprika, garlic powder, and cayenne pepper.
Toss the cauliflower florets in the marinade until thoroughly coated.
Spread the florets on a baking sheet in a single layer.
Roast the cauliflower for 25-30 minutes, flipping halfway through.
While the cauliflower is roasting, prepare the spicy peanut dipping sauce.
In a bowl, mix peanut butter, maple syrup, rice vinegar, and water until smooth.
Taste the sauce and adjust sweetness or spice as needed.
Serve the roasted cauliflower hot with the dipping sauce on the side.