These spooky halloween smores bars have a crumbly graham cracker crust, rich chocolate mousse, and marshmallow spiderwebs.
Line a 9x13 pan with parchment paper, securing it to the sides with clips or tape if necessary. Set aside.
Add the graham crackers to a food processor. Pulse on high until it becomes a fine crumb, stopping and stirring the graham crackers once or twice if needed.
Pour the graham cracker crumbs into a large mixing bowl. Pour over the melted butter and add in the salt and cinnamon. Mix everything together until the mixture looks like wet sand.
Pour the graham cracker crust mixture into the prepared 9x13 pan. Press the crumbs into a single layer with the back of a spoon. Freeze the crust for 15 minutes to set.
Add the chocolate chips to a large heat proof bowl. Set a sieve over the top of the bowl and set aside.
Add the heavy cream, egg yolks, and salt to a medium saucepan. Place the pan over medium heat on the stove top. Whisk the cream mixture continuously until it begins to bubble and is thick enough to coat the back of a spoon, about 6-9 minutes. Pour the cream mixture through the sieve into the bowl of chocolate. Add in the espresso and vanilla extract to the chocolate and cream. Use a silicone spatula to stir the chocolate into the warm cream until the chocolate is completely melted and incorporated into the cream. It should look like one homogenous color and texture.
Pour the chocolate mousse into the pan with the set graham cracker crust. Spread the chocolate mousse from edge to edge of the pan using a silicone spatula. Place the pan in the fridge to set, at least 1 hour or up to overnight.
Place the mini marshmallows in a large microwave safe bowl. Microwave for 30 seconds, and then stir until the marshmallows melt into each other.
Remove the s’mores bars from the fridge. Use the parchment paper to lift the bars out of the pan and place it onto a work surface.
Put on kitchen gloves (if desired) and lightly coat your gloved hands in a neutral cooking oil. Grab a small amount of marshmallows and pull and stretch them across the s’mores bars. Repeat until the desired effect is achieved and you’ve used all of the marshmallows.
Decorate with candy eyes, if desired, while the marshmallows are still soft. Set in the refrigerator for 10 minutes to allow the marshmallows to firm up.
Slice into 12 or 24 individual servings and enjoy!