Set the oven to low broil and place the oven rack near the top. In a medium-sized bowl, carefully pick through the crab meat to remove any shells. Try not to break up the lumps. Be as thorough as possible. In a separate bowl, whisk the egg and then add in the mayonnaise until combined. Add the breadcrumbs and stir to combine. Add the Old Bay, fines herbs and garlic powder. Add the mustard and Worcestershire sauce, stir until well combined. Gently stir the wet mixture into the crab meat, one spoonful at a time. This part takes some patience because you really want to avoid breaking up the lump meat as much as possible. Carefully form 5-6 crab cakes. Lightly grease the bottom of a baking sheet (cooking spray works well for this) and place the crab cakes on the sheet. Place a small piece of butter on top of each crab cake. Broil on low for 12-15 minutes, keeping a close eye to make sure they don't burn. Don't flip them, just allow them to cook on one side the entire time (the lack of filler makes them very delicate). If the tops seem like they're going to burn, lower the oven rack. You're not cooking the meat but you want the filling to solidify and the egg to cook through. If you want the tops a bit more golden, switch the broiler to the high setting for the last minute or so. When the tops are golden brown, remove the pan from the oven and allow the crab cakes to cool slightly before serving. I recommend serving them with Saltine crackers and dijon mustard. They also make a great sandwich.