Place the sweet potatoes in a large bowl filled with cold water. Soak for 1 hour.

Preheat the oven to 400 degrees F. Grease 2 sheet pans with 1 tablespoon vegetable oil each.

To make the spice mix, combine the paprika, onion powder, garlic powder, cayenne pepper, salt and black pepper.

Pat the sweet potatoes dry with a paper towel before tossing them in the remaining oil and the spice mix. Divide the sweet potatoes between the sheet pans arranging them in a single layer.

Bake for 25-30 minutes, switching the pans halfway through, until the sweet potatoes are deep golden brown. Serve immediately.