Set the oven to broil and place the oven rack near the top.
In a medium sized bowl, gently pick through the crab meat to remove any shells. Try not to break up the lumps.
In a separate bowl, beat the egg and then whisk in the mayonnaise until well combined.
Add the breadcrumbs, Old Bay, fines herbs, garlic powder, mustard and Worcestershire sauce, stirring until well combined.
A little bit at a time, gently fold the wet mixture into the crab meat. This part takes some patience because you really want to avoid breaking up the lump meat.
Using a kitchen scale, weigh out 3 ounce sliders. Depending on the size of the slider buns you might want to slightly increase or decrease the size.
Lightly grease the bottom of a baking sheet (baking spray works well) and place the crab cake sliders on the sheet.
Place a small piece of butter on top of each crab cake.
Broil for 10-15 minutes, keeping a close eye to make sure they don't burn. Don't flip the cakes, 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 or switch the broiler to a lower setting. You're not cooking the meat but you want the filling to solidify and the egg to cook through.
When the tops are golden brown, remove the pan from the oven and allow the crab cakes to cool slightly before serving.