Preheat oven to 350 degrees F. Lightly oil a 9-inch baking dish or coat with nonstick spray.
Place broccoli florets into a steamer or colander set over a pan of boiling water. Cover and steam for 5 mins, or until cooked through and vibrant green.
Spread mashed potatoes into the prepared baking dish; sprinkle with cheeses, topped with broccoli.
Place into oven and bake until heated through and the cheese has melted, about 10-12 minutes.
Serve immediately, sprinkled with Corn Flakes, if desired.
Notes
*Ritz Crackers can be substituted.Adapted from Skinny Mom