Combine first 6 ingredients in a large bowl. Add 1 cup melted butter, 4 cups breadcrumbs, and next 3 ingredients. Spoon crabmeat mixture into 10 baking shells or individual baking dishes.
Top servings evenly with remaining 1 cup breadcrumbs; drizzle evenly with remaining 1/2 cup melted butter. Bake, uncovered, at 400° for 20 minutes or until thoroughly heated. Turn oven setting to broil. Broil 3 minutes or until golden brown. Serve immediately.