S’mores Slab Pie
for the Pate Brisee, bottom crust
4 cups all-purpose flour
2 tablespoons sugar
1 1/2 teaspoons salt
16 tablespoons (2 sticks) cold, unsalted butter, cut into small cubes
3/4 cups ice water
for the pie
14 full sheets (about 7 ounces) graham crackers
1/2 heaping cup old fashioned oats
1/4 cup brown sugar, packed
1/2 teaspoon cinnamon
1/4 teaspoon salt
1 teaspoon vanilla
6 tablespoons unsalted butter, melted
18 ounces chocolate chips (use your favorite, milk, dark, white, or a mix)
6 ounces miniature marshmallows (about half a standard bag)
Special equipment: a half sheet pan (about 13″x18″)
1. Make the dough for the bottom crust: place the flour, sugar and salt in the bowl of a food processor* and pulse 2 or 3 times to mix. Add the very cold butter and pulse until the mixture becomes course with pea-sized butter clumps here and there. With the machine running, drizzle in the water and allow to mix until the dough comes together (often described as “riding the blade,” because the dough ball clings to it and circles the bowl rather than being cut through by the blade).
2. Turn out the dough onto a well-floured surface and kneed once or twice to bring all the scraps together. Press the dough into a rough a rectangle, wrap in plastic wrap and refrigerate for at least an hour.
3. Meanwhile, prepare the graham cracker topping: Break up the graham sheets into 1″ pieces and add to the bowl of a food processor. Pulse two or three times to reduce the crackers into a pea-sized bits. Add the oats, brown sugar, cinnamon and salt and pulse to mix. Pour in the melted butter and vanilla and pulse until the mixture becomes clumpy and sticks together when pinched.
4. Preheat the oven to 350°F and position a rack in the center.
5. Prepare the crust: let the chilled dough warm up for a couple of minutes, then place on a large, well-floured board or rolling mat. Roll out the dough in a rectangle about 16″ x 20″ (if you’re using a baking sheet smaller than a half sheet pan, roll out the dough to these dimensions anyway, or your crust would be too thick). Don’t worry if there are cracks and fissures – you can patch them once they’re in the pan.
6. Transfer the dough to a parchment sheet lined pan, and gently press the dough smoothly into the pan’s edges and corners. Trim any overhang to about an inch.
7. Assemble the pie: pour the chocolate chips on the crust and spread evenly. (The chips do not have to completely cover the crust – they will spread as they melt.) Dot the chocolate layer with marshmallows (again, the marshmallows will not completely cover the chocolate). Spoon the graham cracker mix over the top (it’s okay if the marshmallows peek out – do try to cover the chocolate, though). With the palm of your hand, gently press down on the graham mixture. Fold the dough edges over onto the pie top to create a little containing rim.
8. Bake for 30 minutes. The marshmallows should be puffy and lightly browned on the top. Remove from the oven and allow to cool for one hour. Slice and serve to your cheering crowd.
9. The pie is best served on the same day it’s made, warm and gooey. To reheat, warm in a 300°F oven for 10 minutes.
*This recipe pushes the limits of my 9-cup food processor. If you have a smaller machine, you’ll need to work in two batches, and then combine the dough balls in the second step. Or, prepare the dough by hand in a bowl, working the butter into the flour using a pastry blender or your fingers.