Chocolate Chip Graham Cracker S'mores Sandwich Cookies

Ingredients

• 1/2 cup softened butter
• 3/4 cup light brown sugar
• 1/4 cup granulated sugar
• 1 teaspoon vanilla extract
• 1 egg
• 2 cups ground graham cracker crumbs, divided
• 3/4 cup all purpose flour
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 1 1/4 cups chocolate chips
• 3/4 cup marshmallow fluff
• 10 ounces good quality chocolate, chopped and melted