In a bowl, gently combine crab meat, almond flour, mayonnaise, egg, Dijon mustard, Old Bay, and green onions, being careful not to break up the crab too much.
Form mixture into 8 patties. Chill 20 minutes.
Melt butter in a skillet over medium heat.
Cook crab cakes 3–4 minutes per side, until golden brown and heated through.