Step 1

Preheat your oven to 350 degrees.

Step 2

Lightly grease a 9-inch x 13-inch glass baking pan and line it with parchment paper, so the paper hangs over the sides a little. Set it aside.

Step 3

Put the butter, white sugar, and brown sugar in the bowl of your mixer (or a large bowl if mixing by hand). Cream them together until uniform.

Step 4

Toss in the eggs and vanilla. Beat until the mixture thickens a little and fluffs up.

Step 5

In a separate bowl, mix together the graham cracker crumbs, flour, baking powder, and salt until uniform.

Step 6

Toss the dry mixture into the butter / sugar mixture. Beat to incorporate, just until all the ingredients come together.

Step 7

Gather the dough into a ball. Whack it in half with a bencher or sharp knife.

Step 8

Take one half, plop it in your prepared pan, and smoosh it down so that it covers the bottom of the pan completely in an even layer.

Step 9

Unwrap all your chocolate bars. Cover the dough with a single layer of chocolate, cutting the bars as needed to fit your pan. It doesn't have to be a perfect fit (after all, it's going to melt). Just do the best you can.

Step 10

Next, cover the chocolate in an even layer of marshmallow fluff.

Step 11

Add the top crust: Grab the other half of the dough. Smoosh it flat on a lightly floured board. Make it roughly the same size and shape as your pan, so you know it'll be big enough to cover the whole top. Slice it into strips. Lay each piece on top of the fluff until you've covered the whole pan (see photos in original post).

Step 12

Pop the pan into your preheated oven. Bake at 350 degrees for about 30-35 minutes, until the top is golden brown.

Step 13

Yank the pan out of the oven. Let it cool completely on a rack.

Step 14

When cool, slice into fat wedges and share with your favorite people. Enjoy!