On a rimmed sheet pan, toss the mushrooms with oil (they’ll absorb it). Sprinkle over the mushrooms: the salt, black pepper, and Cayenne pepper. Toss until evenly coated. Spread out so they’re not touching one another; otherwise, they’ll steam.
Bake for about 35 to 40 minutes in total, flipping once midway through, until they’re crispy and browned with just the slightest spot of chewiness remaining in the center.
Ella Quittner is a contributing writer and the Absolute Best Tests columnist at Food52. She covers food, travel, wellness, lifestyle, home, novelty snacks, and internet-famous sandwiches. You can follow her on Instagram @equittner, or Twitter at @ellaquittner. She also develops recipes for Food52, and has a soft spot for all pasta, anything spicy, and salty chocolate things.