Line an 8"-x-8" pan with foil and spray with cooking spray. Make graham cracker crust: In a large bowl, stir together graham cracker crumbs, butter, sugar, and salt until completely moist. Press into prepared pan until packed. Freeze while you make fudge layer and frosting.
Make chocolate fudge: In a small saucepan, combine sweetened condensed milk, chocolate chips, and vanilla.
Make marshmallow frosting: Place a heatproof bowl over a small saucepan of simmering water over medium heat. Whisk together egg whites, water, light corn syrup, and sugar and cook 3 minutes. Using a hand mixer, whip until glossy.
Heat broiler. Pour the chocolate fudge layer over the graham cracker crust and smooth to create an even layer. Then, pour the marshmallow frosting on top and smooth. Broil 2 minutes, then freeze 1 hour. Slice into squares and serve.
Recipe by 5* trending recipes with videos at https://food.theffeed.com/2019/06/01/smores-fudge/