Preheat oven to 425 degrees F and line 1-2 large baking sheets with parchment paper.
In a large bowl toss together the sweet potatoes with the olive oil, ground cinnamon, cayenne pepper and fresh ground salt and pepper. In a separate bowl toss together the zucchini and yellow squash with the olive oil, salt, and pepper until coated.
Transfer the sweet potato rounds and squash to the prepared baking sheets in a single layer. Transfer to the oven and roast for approximately 25 minutes (the sweet potatoes) and 15 minutes (the squash), or until cooked to desired doneness.
Remove from the oven and transfer to a large cast iron skillet or serving platter.
Meanwhile, in a medium bowl, gently toss together the halved cherry tomatoes and the diced bell pepper, red onion, jalapeño, corn, and cilantro.
Top the “nachos” with the fresh mixed veggies, smashed avocado, chopped green onion, green onion, salsa and lots of cotija cheese.