Roast the sweetpotatoes by preheating the oven to 425F.
Line a sheet with parchment paper and add sweetpotatoes.
Toss with olive oil, salt, black pepper, garlic powder, paprika, and cumin.
Roast in the oven for 20-25 minutes until sweetpotatoes are tender, flipping and mixing with a spatula once halfway through. Cool and set aside.
In a large mixing bowl, make the dressing by combining Greek yogurt, mayo, lime juice, garlic, salt, pepper, chili powder and cumin. Mix until completely combined.
To the mixing bowl add cooled sweetpotatoes, corn, scallions, cilantro, jalapeño and cotija cheese. Toss until evenly combined.