Position a rack in the center of the oven and preheat the oven to 350 degrees F. Spray a 9x13 casserole dish with non-stick cooking spray, set aside.

Heat a large skillet on medium-high heat. Add 1 tablespoon of of butter with 1 teaspoon of olive oil and sauté the zucchini squash about 4 minutes, turning half way in between. You want the squash to get nice and brown and not wilted so don't overcrowd the pan. Remove the zucchini to a large bowl. Repeat with the summer squash sautéing in batches until all the squash has been cooked.

Add 1 tablespoon of butter and 1 teaspoon of olive oil to the same skillet and sauté the onions until they turn translucent, about 3-4 minutes. Add onions to the same bowl as the zucchini.

Add 2 tablespoons of butter and 1 teaspoon of olive oil to the same skillet and sauté the crushed crackers for 1-2 minutes or until they start to get golden brown. Add 1/2 of the crackers to the bowl with the zucchini, yellow squash, and onions.

Add the salt, pepper, garlic powder, red pepper flakes, parmesan cheese, sour cream, and cheddar cheese to the bowl and using a spatula stir to combine. Dump the mixture into the prepared dish and sprinkle the remaining cracker crumbs evenly on top. Bake for 20 minutes or until the top is golden.