Preheat the oven to 350°F. Line your pan with parchment paper.
Place the graham crackers in a food processor and pulse until they have turned into fine crumbs. Add the egg, sugar, salt and melted butter. Stir together with a spoon.
10 tbsp unsalted butter, ⅛ tsp salt, 1 tbsp sugar, 1 egg, 18 graham cracker sheets
Transfer the graham cracker mixture to the pan and smooth it evenly. Using your hands, pack the crumbs tightly in the pan, pressing down firmly. Then place the pan in the oven and bake for 12 minutes. Remove the pan from the oven and allow to set for 5 minutes.
Sprinkle on the chocolate chips and place the pan back in the oven for 1 minute. Remove from the oven and use a spatula to smooth the melted chocolate across the graham cracker layer until it is covering every corner. Allow the chocolate to set for about 20 minutes.
⅓ cup dark chocolate chips
After 20 minutes, the chocolate will still be a bit soft. Pour the marshmallows onto the chocolate and gently push them in. If you have any large gaps, add a few more marshmallows. Allow the bars to solidify at room temperature for another 20-30 minutes.
1½ cups mini marshmallows
Using a blow torch, carefully toast the marshmallows just until they are golden brown. Allow the marshmallows to cool for a couple minutes before slicing into bars.