In a large bowl, stir together the drained crab meat, almond flour, parsley, green onion, Old Bay, salt, and pepper. Crab meat should remain in small lumps. Stir in the egg, mayo, and mustard, until incorporated.
Form mixture into 4 equal patties, about 1/3 cup each and 3/4- to 1-inch thick. Place patties on a lined plate (with waxed paper, parchment or plastic wrap) and refrigerate for at least 30 minutes.
Spray or brush the air fryer basket with oil. Brush melted butter onto both sides of each crab cake and place in air fryer basket.
Air fry at 350°F for 10 minutes, carefully flipping each crab cake halfway through.
Serve crab cakes with lemon wedges and a sauce, if desired. (See blog post for sauce recipes.)
Notes
If you prefer to cook the crab cakes in a skillet, melt butter over medium heat and fry crab cakes for 3-4 minutes each side.