In a medium mixing bowl, combine flour, sugar, cocoa powder, and baking soda.
In a small bowl, beat together the vanilla, egg, sour cream, milk, and vegetable oil.
Gently add wet ingredients to dry mixture. Stir until combined.
Spoon batter into a greased donut pan. Bake for 8 minutes or until donuts test done.
Remove from oven. Set aside to cool before topping with Marshmallow Creme Frosting. Frost donuts, top with mini chocolate chips and graham cracker crumbs.