For the shrimp burgers: Coarsely chop half of the shrimp. Put the remaining shrimp in a food processor and pulse until smooth. Combine both shrimp in a large bowl with the breadcrumbs, lemon juice, salt, garlic powder, pepper, scallions and egg and mix. Refrigerate for 10 minutes, and then form into 4 patties. Refrigerate 10 more minutes.
Heat the oil in a large cast-iron skillet over medium-high heat. Cook the burgers, about 3 minutes per side.
For the Old Bay mayo: Combine the mayonnaise and Old Bay to taste in a small bowl.
To serve, spread the buns with the mayo and place the burgers on the buns. Top the burgers with the avocado slices, lettuce leaves and tomato slices.
Recipe courtesy of Katie Lee