Imagine your favorite shrimp salad was compacted into a grab-and-go burger topped with a smoky avocado cream. The shrimp is chopped into 1/4-inch pieces, so you get full chunks of sweet shrimp with every bite. It’s like all of your favorite summer components made into one.
For the shrimp burgers: Pulse the butter crackers in a mini food processor until fine crumbs form; you should have about 1 cup. Transfer to a medium bowl and set aside. Wipe out the mini food processor.
Heat 2 tablespoons canola oil in a large nonstick skillet over medium-high heat. Add the onions and celery and cook, stirring occasionally, until softened and slightly translucent, about 3 minutes. Season with salt and pepper, transfer to a plate and set aside to cool. Wipe out the skillet.
Meanwhile, dice the shrimp into 1/4-inch pieces, then run your knife through half of the chopped shrimp once more. Transfer the shrimp to the bowl with the cracker crumbs. Stir in the cooled onion and celery mixture, dill, honey, mustard powder, seafood seasoning, egg, garlic, lemon zest and 3/4 teaspoon salt until the cracker crumbs fully absorb any moisture. Form the mixture into 4 patties, transfer to a plate and refrigerate for 30 minutes.
Preheat the broiler to high or preheat the oven to 450 degrees F. Place the buns on a baking sheet and broil or bake until golden, 1 to 2 minutes.
Heat the remaining 1/2 cup oil in the same skillet over medium-high heat. Line a plate with paper towels. Add the shrimp patties and cook until golden brown, 4 to 5 minutes per side. Transfer to the prepared plate.
For the avocado mayo: Put the mayonnaise, sweet chili sauce, seafood seasoning, Worcestershire sauce, paprika, cayenne, avocado, garlic and lemon juice in a mini food processor. Blend until smooth and transfer to a small bowl. Stir in the scallions.
Serve the shrimp burgers on the toasted buns with lettuce, tomato and the avocado mayo.