Clean morels thoroughly, rinsing the insides as best as possible. Cut stem down to 1 inch to create a clear opening to insert stuffing.
Toast pine nuts in a dry skillet over medium-low heat, shaking frequently until golden brown, about 5 minutes. Let cool; chop finely.
Combine pine nuts, crabmeat, Parmesan cheese, mayonnaise, thyme, pepper, garlic powder in a food processor; pulse into a fine paste.
Spoon crab paste into a heavy-duty plastic bag and snip off 1 corner with scissors. Pipe paste into morels.
Preheat the oven to 350 degrees F (175 degrees C). Line a baking sheet with aluminum foil and grease with butter.
Beat 2 egg whites in a bowl. Place bread crumbs in a second bowl. Roll stuffed morels in the egg whites, then coat evenly with bread crumbs. Place morels on the prepared baking sheet, leaving plenty of space between them.
Bake in the preheated oven until golden brown, 15 to 18 minutes. Flip morels and rotate the baking sheet every 5 minutes to ensure even baking. Serve while still warm.