Heat a nonstick skillet over medium heat. Once heated, spray with nonstick cooking spray and place 1 whole wheat tortilla in the pan.
Place half the cheese on the tortilla. You really don't need much, just enough to act as a glue. Top the cheese with the beans, corn, and avocado. Sprinkle the remaining cheese on top of that, again just enough to act as a glue, and top with the remaining tortilla. Spray the outside of the top tortilla with cooking spray.
Cook for about 1 - 1 1/2 minutes, then using a large spatula, flip it over. Cook on the other side for about another minute. Just until all the cheese is melted and both tortillas are browned.
Let it cool for just a minute before cutting into four pieces. Feel free to top with salsa, sour cream, cilantro, or any topping of your choosing!
If freezing, be sure to let them cool completely to room temperature (never freeze hot/warm food). Store them in an airtight container, vacuum seal, or in a freezer zippie.