Finely chop 8 oz of fresh button mushrooms in food processor. Coarsely chop by hand 8 oz fresh button mushrooms. Place in a large bowl.
2
Add bread crumbs, onion powder, garlic powder, flour, salt
3
Place a sheet of plastic wrap on a large plate. Using a metal ring the size of a hamburger (spray lightly with cooking spray) place 1/4 to 1/3 cup of the mushroom mixture into the ring. Press with a rubber spatula to firmly set the mixture. Repeat for each mushroom burger. Cover lightly with the plastic wrap and refrigerate for at least 1 hour.
4
Heat a large non-stick skillet over medium-medium high heat. Add olive oil and heat the oil. Carefully flip mushroom burger onto the palm of your hand and gently place into skillet. Cook the patties about 3-4 minutes, flip when browned. Cook 3-4 minutes on other side. Serve on a toasted hamburger bun and serve with garlic aoli (mayonnaise mixed with lemon juice).