1. Preheat oven to 400º. Peel 4 medium sweet potatoes. Halve length-wise, and slice crosswise to 1/2 inch thick. Toss potatoes with olive oil and season with salt.

2. Spread potatoes in one single layer on a baking sheet. Cook until tender, tossing occasionally, 25 to 30 minutes.

3. Sprinkle with butter cut into small pieces, light-brown sugar, pecans and cayenne pepper.

4. Bake until sugar is caramelized and hard about 10 minutes. Toss gently and serve immediately.