In a large bowl combine the mayonnaise, egg, Old Bay, dijon mustard, lemon juice and saltine cracker crumbs. Stir well.
Fold in the drained lump crab meat gently until all the crab is evenly coated.
Cover the bowl with plastic wrap and refrigerate for at least 30 minutes
Preheat the oven to 450 and line a baking sheet with parchment paper or spray with non-stick cooking spray.
Scoop the crab mixture out in 1/2 cup portions into a mound on the prepared baking sheet. Gently press it together to hold into place if it falls apart. I like to use a measuring cup or large ice cream scoop for this.
Brush the tops of the crab cakes with melted butter.
Bake crab cakes for 13-15 minutes or until the tops of the crab cakes are a nice golden brown.
Serve warm.
Store any leftovers in an air tight container in the refrigerator.