Prepare a 12 X 17" sheet pan by lining it with parchment paper. Set aside.

In a heavy duty, thick bottomed pot, combine all salted caramel ingredients.

Over medium heat, stirring constantly, cook ingredients until they are all dissolved and combined.

Turn heat to medium high. Stirring constantly, cook until caramel reaches 242F. This will take about 40 minutes. Trust your thermometer. Keep going.

Turn off heat once temperature reaches 242F. Pour into prepared parchment. Set aside approximately ⅓ cup of the caramel in a microwaveable safe dish. Cool for a minimum of 4 hours.

Prepare your workspace. Set out mixer, cooled caramel, caramel you have set aside for decorating, hot water bath, and weighed out ingredints.

Combine cold coffee and unflavored gelatin. Set aside while you cook the marshmallow syrup.

In a heavy duty, thick bottomed pot, combine coffee concentrate, white sugar, brown sugar, and corn syrup. Cook over medium high heat until 250F. This takes about 15 minutes. Turn off heat. Let syrup sit undisturbed until it reaches 212F.

While your syrup rests, put your hydrated gelatin into a hot water bath (the bowl of gelatin into another bowl of hot water. Don't add water TO the gelatin mix). This will liquify the gelatin to a smooth state.

Add liquid gelatin to the 5 quart mixing bowl. Add cooled syrup to this. Using the whisk attachment, mix on high for 8 minutes or until marshmallow has doubled in size.

Spread marshmallow evenly over salted caramel. Once you have spread it, microwave caramel you had set aside in 30 second intervals until it is fluid.

Swirl the warm fluid caramel into the marshmallow. Use a knife to make designs.

Sprinkle a small amount of instant espresso powder overtop. Go lightly with this.

Lightly oil a sheet of parchment paper big enough to cover the marshmallow. Place it overtop, and smooth it out with very gentle pressure. Let marshmallow set up for 24 hours before cutting.

Spray a knife with cooking spray. Cut caramel marshmallows into desired size. I recommend 1" by 1.5". Wrap in clear candy wrap or parchment paper.