Start by preheating your waffle maker to medium high heat.
In a large bowl, whisk together flour, graham cracker crumbs, baking powder, sugar and salt.
In a separate bowl, mix together milk, eggs, melted butter, and vanilla.
Slowly pour wet ingredients into dry ingredients bowl. Whisk until combined.
Heat up a waffle iron, spray with cooking spray, and ladle in about ¾ of batter. Cook for about 5 minutes each, or until golden brown.
When the waffle is done, cut it in half. On one half, add a few tbsp of chocolate chips, and marshmallows, and place the other half on top.
Place the waffle back in the waffle iron for 1-2 minutes, or until the chocolate and marshmallows melt.
Drizzle the waffle with chocolate syrup and serve immediately.