Preheat your oven to 375 degrees F and thoroughly grease a standard-sized muffin tin with nonstick cooking spray.

In a bowl, mix together cooked beef, taco seasoning, and tomatoes until well combined.

Place a wonton wrapper in each cup of the prepared muffin tin.

Spoon 1.5 tablespoons of the taco mixture into each cup, then sprinkle 1 tablespoon of cheese on top.

Press down gently, then add another layer of wonton wrapper, taco mixture, and a final layer of cheese.

Bake in the preheated oven for 11-13 minutes, or until the cups are heated through and the edges are golden brown.