• Line a 9 x 9-inch baking pan with parchment paper or foil, leaving an overhang on the sides for easy removal. Grease lightly with cooking spray or butter.
• In a bowl combine the graham cracker crumbs with the melted butter, until the mixture resembles wet sand.
• Press the mixture firmly and evenly into the bottom of the prepared baking pan and set aside.
• Preheat your oven to 350°F.

Make the Brownie Batter:

• In a heatproof bowl, melt the butter and dark chocolate together using a microwave or a double boiler until smooth. Allow to cool slightly.
• Whisk the sugar, eggs, and vanilla extract in a separate large bowl until well combined and fluffy like a mousse.
• Gradually pour the cooled melted chocolate into the egg mixture and whisk constantly until smooth and well combined.
• Sift the flour, cocoa powder, and salt into the wet ingredients. Gently fold the dry ingredients into the wet until just combined. Be careful not to overmix.
• Pour the brownie batter over the graham cracker crust, spreading it out evenly.
• Bake in the preheated oven for about 25 or 30 minutes, or until a toothpick inserted into the center comes out mostly clean with a few moist crumbs. Allow the brownies to cool slightly.

Make the Marshmallow Topping:

• In a bowl pour in ½ cup of the cold water. Sprinkle the gelatin over the water and let it sit to bloom.
• In a medium saucepan, combine the remaining 1/4 cup of water, granulated sugar, honey, and salt. Cook over medium heat, stirring occasionally, until the sugar dissolves.
• Increase the heat to high and bring the mixture to a boil. Continue to cook without stirring until the syrup reaches 240°F on a candy thermometer.
• Slowly pour the hot syrup into the gelatin mixture, while mixing on low speed. Gradually increase the mixer speed to high and whip until the mixture becomes thick and glossy and the bowl feels lukewarm to the touch, about 10 to 12 minutes. Add the vanilla extract and mix until incorporated.
• Immediately spread the marshmallow mixture evenly over the cooled brownies.

Bake the Brownies:

• Switch the oven to broil. Place the brownies back in the oven for about 1 or 2 minutes, watching very closely, until the marshmallow layer is toasted and golden brown. Be careful not to burn it.
• Allow the brownies to cool completely in the pan on a wire rack.
• Once cooled, use the foil overhang to lift the brownies out of the pan and onto a cutting board. Cut into squares and serve.