Make the burger patties: In a large mixing bowl, mix the ground beef, breadcrumbs, egg and all the seasonings (coriander, cumin, cinnamon, paprika, salt, and pepper) until combined.
Scoop about ¼ cup of the mixture, roll it between your hands and then flatten it to form a burger patty.
Cook the patties: Heat the oil in a large frying pan on medium heat, and cook the patties for 4-5 minutes.
Flip the burgers on the other side, then add a slice of cheese to each patty and let it melt while the patty is cooking (don't overcook).
Assemble the burger: Cut one of the burger buns open, add lettuce, a burger patty topped with cheese and, finally, a teaspoon of guacamole.
Notes
Storing: Store leftovers cooked beef patties in an airtight container in the fridge for up to 4 days. Reheat in the microwave for 10-20 seconds.