Cover a mold or baking sheet of 1.5 inches high x 5 inches long x 3 inches width approximately with parchment paper. Dust over the parchment a fine layer of cornstarch and reserve.
Hydrate the gelatin with 2 tablespoons of cold water.
Whip the egg whites until they reach stiff peaks.
In a medium sized pot cook the sugar and 45 grams of water. When the mix bolis, add the liquid glucose and continue cooking until it reaches 242 F/117 C. Take off the stove and add the hydrated gelatin. Mix until it dissolves
While whipping at high speed, add the syrup slowly to the beaten egg whites. Then, add the vanilla extract. Continue whipping until the marshmallow mix reaches room temperature, then immediately spread evenly over the prepared baking sheet / mold.
Allow to rest at least 1 hour in the fridge.
Meanwhile, prepare the chocolate. Melt the chocolate and mix with the cacao nibs. Cool slightly and then spread over parchment paper into a 3x5 inch square. Allow to begin to solidify and cut into 6 squares.
Once the marshmallows are ready, trim the edges with a hot knife and cut into 6 squares or remove from the mold.
Build the smores. Sandwich the chocolate and marshmallow squares between two cookies. Bake at 450 F/230 C for 5 minutes or until the marshmallow begins to melt and caramelize on the outside. If you have a kitchen torch you can use it as well to melt the chocolate and caramelize the marshmallows. Sprinkle sea salt over the s'mores to finish.