Preheat the oven to 350 F. In a medium bowl, whisk together flour, salt, and baking soda. In a large bowl, combine butter with both granulated and brown sugar until fluffy.
Add in the egg and vanilla extract and mix until smooth. Fold in the flour mixture, and mix until it is fully combined. Fold in the chocolate chips, crushed graham crackers, and mini marshmallow bits.
Roll the cookie dough into balls, and place them onto a large ungreased baking sheet. Bake for 10-12 minutes. Remove from the oven, and place one chocolate kiss on each cookie.
