Combine the avocado, onion, jalapeño, lime juice, salt and garlic powder in a large bowl.
Use a sturdy fork or potato masher to mash together until desired consistency is reached.
Stir in the cilantro, taste and season with more salt if desired. Sprinkle the cotija cheese on top just before serving. Enjoy right away or place plastic wrap directly on top of guacamole and place in fridge until ready to eat.
Notes
Guacamole can be made up to 2 days in advance when stored properly - keep the avocado pits in prepared guacamole and place plastic wrap directly on top of guacamole, removing as many air bubbles as possible. Store in fridge, remove pits and stir before serving.