Preheat the oven to 400° F and grease a large baking sheet with cooking spray. Place the sliced sweet potatoes in a large mixing bowl and toss with olive oil, salt, and pepper. Arrange the seasoned sweet potatoes in a single layer on the baking sheet with a little room in between each one and bake for 12-15 minutes, until they start to brown around the edges. You might need to work with two baking sheets.
Transfer the potatoes to a 12'' cast iron skillet and layer with frozen corn and shredded cheese. Bake for 5-10 minutes, or until the cheese is melted and bubbly.
Remove the skillet from the oven and top with sliced jalapeño, avocado, red onion, and cilantro. Serve immediately.
Notes
Longer and skinnier sweet potatoes are best for this recipe. If you can't find a large one, 2 smaller ones will work.