Preheat oven to 425 degrees. Coat a 9 x 9” baking pan with cooking spray.
In a microwave-safe bowl, add onions, red peppers, and butter. Cook in microwave on high for about 4 minutes until soft. Set aside.
In a large bowl, mix together cream-style corn, beans, cottage cheese, egg, chili powder, and cumin. Blend well. Stir in cornbread mix and only stir until blended. The batter might be a little lumpy. Using a rubber spatula, spread cornbread batter into prepared pan.
Spoon cooked onions, red peppers, and liquid left in the bowl, evenly over top of cornbread.
Pour ½ cup enchilada sauce all over onions. Using the same rubber spatula, carefully spread yogurt evenly over the top. It’s okay that it doesn’t cover over the entire casserole.
Bake for 55-60 minutes so the casserole will be cooked through. It will look very brown.
Refrigerate for at least 1 hour before cutting into 6 slices. It’s very soft and needs to firm up in the refrigerated or it will be a mushy mess. I like to make this casserole the day before serving, refrigerate, cut into slices, and reheat. It also freezes great after it’s baked, refrigerated and sliced.