Mix softened butter and brown sugar. Add eggs, water, and vanilla. Mix until incorporated.
Combine dry ingredients together, and add a little at a time to the wet ingredients.
Add chocolate chips, just until mixed. Add in graham cracker mixture, mixing with your fingers.
Roll dough into small balls and place on a greased cookie sheet. Bake at 350 degrees for around6 minutes.
While cookies are baking, cut marshmallows in half. After 6 minutes press in half of a marshmallow.
Return to the oven for 2 more minutes. Then remove and add a chocolate candy bar piece.