Preheat the oven to 350F. Add butter, brown sugar, and sugar to a bowl. Whisk until well combined.
Add yogurt and vanilla and mix again.
Add flour, baking soda, and salt. Mix until just combined.
Add 2 tbsp of chocolate chips and stir to combined.
Place a graham cracker down on a lined baking sheet. Add remaining chocolate chips, and a marshmallow.
Shape all the cookie dough into a disk and shape it over the marshmallow. Transfer to the freezer for 10 minutes, then bake for 10-12 minutes.
Top with flaky salt and enjoy!