1. Combine egg yolk with mayonnaise, seasoning, cayenne pepper, and mustard in a bowl, and whisk thoroughly. Then add the crab meat and salt to taste. Combine the mixture till it’s even.
2. Spread crushed cornflakes over a baking pan. Make ten equal patties from the crab meat mixture and form patties with them. Then, pat the patties over the crushed flakes till they’re fully coated.
3. Transfer the patties to a baking pan lined with plastic wrap. Cover the pan with some plastic wrap, and place the tray in the fridge. Leave it to chill for about 3-4 hours.
4. Set the oven to 400F and while you wait, move the chilled patties to an oiled baking sheet. Add half a teaspoon of butter on top of each cake.
5. Toss the sheet in the oven and bake for about 15 minutes, or until the cakes are golden brown.

Another helpful method is described in this video recipe.