Preheat the oven to 350º F. Lightly spray a regular sized muffin pan with non-stick cooking spray. In a medium sized mixing bowl, combine the graham cracker crumbs, melted butter and sugar. Stir until well mixed and crumbs resemble wet sand. Place 1 & 1/2 to 2 tablespoons of graham cracker crumbs in each muffin well. Press them down firmly into the pan. I like to use a 1/2 cup or something similar to help me compact the crumbs. Bake that first layer for 5 minutes.
2 cups (226g) graham cracker crumbs, 1/2 cup (113g) butter, 1/2 cup (99g) sugar
Remove the pan from the oven and add add mini marshmallows and chocolate chips to each muffin well. Measuring is not crucial! Add as many or as few as you’d like. Then add another layer of graham cracker crumbs (1 & 1/2 to 2 tablespoons again) on top of the marshmallows and chocolate chips. Use a cup to press the crumbs down firmly. Bake for 4 minutes.
chocolate chips, mini marshmallows
Remove the pan from the oven and add more mini marshmallows and chocolate chips. Place them pan back in the oven, turn the oven to broil to toast the marshmallows until golden, 2-3 minutes. Leave the oven door open partially so you can see how toasty the marshmallows are getting.
Remove the pan from the oven and allow the s’mores cups to cool for 15 minutes before removing them from the pan. I found it easiest to use a small metal offset spatula around the outside of each s’mores cup to loosen any melted on marshmallow. I then used a spoon to remove the cups from the pan. Once you have the s’mores cups removed from the muffin pan you could heat them up in the oven on a baking sheet before serving or serve them at room temperature. Warning! They are messy and crumbly but delicious!