cut top off of marshmallow. form a hole in center of marshmallow using your finger. fill hole with nesquik.
put top back on marshmallow. (you can use a wooden pick to hold the top in place if needed.) freeze or refrigerate for 15 minutes to adhere top of marshmallow to bottom. Insert long campfire-roasting fork or other long fork or skewer into center of marshmallow and slowly roast over the fire to warm the chocolate and turn the marshmallow golden brown. (Do not burn the marshmallow as the chocolate will not have time to heat up and the outside of the marshmallow will slide off.) Fix as many as you can eat at one time.