Preheat oven to 350. Heat olive oil in a skillet over medium heat. Add onion, cook about 5 minutes, until softened. Add garlic. Cook an additional 30 seconds. Remove from heat. Add onion mixture to a blender or food processor along with remaining sauce ingredients. Blend until smooth.
Spray a muffin pan with cooking spray. Press one wonton wrapper into each muffin tin hole. Add a teaspoon of sauce, followed by a teaspoon of black beans, followed by a teaspoon of cheddar cheese. Repeat with another wonton wrapper, sauce, beans and cheese. Top with a wonton wrapper, sauce and cheese. Cook for 20 minutes. Top with guacamole if desired.
Recipe by https://veggingonthemountain.com/ at https://veggingonthemountain.com/2016/02/mexican-mini-lasagnas/