Graham Crackers:

1. Preheat and Prepare: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
2. Mix Dry Ingredients: In a large bowl, combine the all-purpose flour, whole wheat flour, brown sugar, baking soda, cinnamon, and salt.
3. Add Butter: Cut the cold butter into the dry ingredients using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
4. Combine Wet Ingredients: In a small bowl, whisk together the honey, milk, and vanilla extract. Add this mixture to the dry ingredients and mix until a dough forms.
5. Roll and Cut Dough: Roll out the dough on a lightly floured surface to about 1/8-inch thickness. Cut into squares or rectangles using a knife or cookie cutter. Transfer to the prepared baking sheet.
6. Bake: Bake for 12-15 minutes or until the edges are lightly browned. Allow to cool completely on a wire rack.

Marshmallows:

1. Prepare Gelatin: In the bowl of a stand mixer, sprinkle the gelatin over 1/2 cup of cold water. Let it sit to bloom.
2. Heat Sugar Mixture: In a medium saucepan, combine the remaining 1/2 cup of water, granulated sugar, corn syrup, and salt. Cook over medium heat until the sugar dissolves, then increase the heat to high. Cook until the mixture reaches 240°F (115°C) on a candy thermometer.
3. Mix and Combine: With the mixer on low speed, slowly pour the hot sugar mixture into the gelatin. Gradually increase the mixer speed to high and whip for about 10-12 minutes until the mixture becomes thick and fluffy. Add the vanilla extract in the last minute of whipping.
4. Set Marshmallows: Dust a baking dish with powdered sugar. Pour the marshmallow mixture into the dish, smooth the top, and dust with more powdered sugar. Let it set for at least 4 hours or overnight.
5. Cut Marshmallows: Once set, cut the marshmallows into squares and dust with more powdered sugar to prevent sticking.

Chocolate Ganache:

1. Heat Cream: In a small saucepan, heat the heavy cream until it begins to simmer. Remove from heat.
2. Melt Chocolate: Place the chopped dark chocolate and optional espresso powder in a heatproof bowl. Pour the hot cream over the chocolate and let it sit for 2 minutes.
3. Stir Until Smooth: Stir the mixture until the chocolate is completely melted and smooth. Add sea salt and mix well.

Assemble S’mores:

1. Toast Marshmallows: Toast marshmallows over a campfire, grill, or stovetop until golden brown and gooey.
2. Layer Ingredients: Place a piece of chocolate ganache on a graham cracker, top with a toasted marshmallow, and add another graham cracker on top to form a sandwich.
3. Serve and Enjoy: Serve immediately and enjoy your gourmet s’mores!