Preheat the oven to 350°F (176°C).
Cream together butter, sugar, brown sugar, egg, and vanilla.
When well combined, add flour, baking soda, and salt.
Mix with a hand mixer until well combined, and fold in chocolate chips by hand.
Scoop onto a greased baking sheet, as shown.
Bake for 8 minutes until golden brown.
Place half a graham cracker, one cookie, and one marshmallow onto a baking sheet.
Layer as shown. Broil in oven for 30 seconds until marshmallows are golden brown.
Add one Hershey bar on top while still hot. Serve and enjoy! *Makes about 16 cookies.