For the graham crackers:
3/4 cup whole-wheat flour
1/2 cup all-purpose flour, plus more for dusting the rolling pin
1/2 cup unsweetened cocoa powder
1 teaspoon baking powder
1/4 teaspoon fine salt
1 cup granulated sugar
8 tablespoons unsalted butter (1 stick), at room temperature
1 large egg, at room temperature

To assemble the s’mores:
9 tablespoons creamy peanut butter or spiced cookie butter (or one per sandwich)
1 bag large marshmallows (you need about 25 or so; depends on how much mallow you want for your ‘wich)
9 wooden or metal skewers (soak wooden skewers in water for 30 minutes to avoid burning)

Whisk together the flours, cocoa powder, baking powder, and salt in a medium bowl; set aside.
Place the sugar and butter in the bowl of a stand mixer fitted with a paddle attachment and mix on medium speed until light and fluffy, stopping and scraping down the bowl halfway through, about 3 minutes total. Add the egg and beat until incorporated. Stop the mixer and scrape down the sides of the bowl. Turn the mixer to low speed, slowly add the dry ingredients, and mix until just incorporated.
Divide the dough into 2 equal portions and shape them into 1-inch-thick squares. Wrap each tightly in plastic wrap and refrigerate for at least 30 minutes. Meanwhile, heat the oven to 350°F and arrange 2 racks to divide the oven into thirds.
Unwrap 1 dough portion and place it on a sheet of parchment paper. Lightly flour a rolling pin, then roll the dough into a rough 10-1/2-inch square. (If the dough becomes too soft and difficult to handle, place it back in the refrigerator to firm up.)

Trim dough into square, then cut into 9 3-inch pieces. Don’t separate the squares. Slide the parchment and dough onto a backing sheet and set aside at room temperature. Repeat for the other portion of dough.

Place both baking sheets in the oven and bake for 8 minutes. Rotate the sheets from front to back and top to bottom, and continue baking until the graham crackers are fragrant and crisp around the edges, about 7 minutes more.
Remove from the oven and transfer the crackers on the parchment sheets to a work surface. Let cool for 5 minutes. Using your hands, break the crackers into squares using the marked lines as a guide. Immediately transfer the crackers to a wire rack to cool completely.

To assemble the s’mores:
For each s’more, spread 1 tablespoon of the peanut or cookie butter on 9 of the graham crackers; set aside.
Thread 3 marshmallows onto a skewer and roast until golden brown and toasted on all sides.
Carefully place the roasted marshmallows on the peanut or cookie butter side of 1 graham cracker and top with a second plain graham cracker. Gently squeeze the crackers together and remove the stick. Serve immediately. Repeat to make additional s’mores.