Step 1

Add the chocolate and butter to a heatproof glass or metal bowl.

Step 2

Heat the cream on the stovetop (or the microwave) until hot.

Step 3

Pour the cream over the chocolate, making sure it is completely submerged. Let the cream sit for 2-4 minutes without disturbing it.

Step 4

Gently whisk the cream until it is fully combined and the result is a shiny, silky chocolate ganache. Let cool until it is thickened.

Step 5

With an electric mixer using the whisk attachment, whip the heavy cream until medium-stiff peaks form, about 3 minutes. Remove the whipped cream from the bowl and set aside.

Step 6

Place the cream cheese in the now-empty mixing bowl, along with the sugar. Whip on medium speed until completely smooth, about 2 minutes, scraping down the bowl halfway through. Scrape down the sides of the bowl and add the marshmallow fluff. Mix together until just fully combined.

Step 7

Add ⅓ of the whipped cream to the marshmallow mixture and fold it in with a rubber spatula by hand until it is completely combined.

Step 8

Add the remaining whipped cream to the bowl and gently fold it in, being careful not to deflate it.

Step 9

Line a 9” square baking dish (see note about other containers) with 1 long piece of plastic wrap or parchment paper so that it covers the bottom and up 2 of the sides, and it leaves some overhang. This will help release the cake later.

Step 10

Line the entire bottom with graham crackers, cutting any crackers as needed so the bottom is covered completely.

Step 11

Spread half of the marshmallow cream filling evenly on top of the graham crackers.

Step 12

Spread half of the cooled chocolate ganache evenly on top of the marshmallow.

Step 13

Place another layer of graham crackers on top of the chocolate, making sure it is covered completely.

Step 14

Repeat the process with one more layer of marshmallow cream, and chocolate ganache.

Step 15

Then cover only half of the chocolate with the last layer of the graham crackers.

Step 16

Cover the dish and let rest in the refrigerator for 8-12 hours.

Step 17

Transfer the dish to the freezer to let chill for at least 1 hour before ready to serve.

Step 18

Once ready to serve, remove from the freezer. Run a dull butter knife under hot water, and then run it along the edges of the cake, to release the sides from the pan. Then carefully lift the cake out of the pan. See notes from troubleshooting.

Step 19

Place cake on a cutting board and cut in half along the edge of the graham crackers. Carefully place the half with the graham cracker on top of the layer with the ganache so you have tall loaf cake.

Step 20

Place the cake on a platter and carefully spread marshmallow cream on the top layer. Decorate as desired with pieces of graham crackers, marshmallows and chocolate.

Step 21

Use a kitchen torch to toast the marshmallows on top.

Step 22

Let the cake sit for 5-10 minutes to soften up, and then slice and serve.