Put the eggs in a saucepan and cover them with cold water by about 1 inch.
Bring the water to a boil over medium-high heat.
Cover the pan, remove it from the heat, and let the eggs sit for 11 to 12 minutes.
Transfer the eggs to ice water and chill them for 5 minutes.
Peel the eggs and dry them.
Slice the eggs lengthwise and pop the yolks into a bowl.
Add the avocado, mayonnaise, lime juice, onion, cilantro, tomato, jalapeño, garlic powder, cumin, salt, and pepper.
Mash until mostly smooth, leaving a little texture for a more guacamole-style bite.
Spoon or pipe the filling into the egg whites.
Sprinkle with chili powder or Tajín.
Garnish with extra cilantro or diced tomato if you like.
Chill the tray for 15 to 20 minutes before serving.