Maple-Walnut Graham Crackers

Adapted from a recipe by Lucy Baker at Serious Eats. http://bit.ly/eEN30s

• Ready In: 1 hr
• Serves: 12
• Yields: 24 crackers

Ingredients

• 3⁄4 cup  whole walnuts
• 1 1⁄2 cups all-purpose flour
• 1⁄2 cup whole wheat flour
• 1  cup  lightly packed dark brown sugar
• 1  teaspoon baking soda
• 3⁄4  kosher teaspoon salt
• 7  tablespoons unsalted butter, cut into cubes and frozen for 10 minutes
• 1⁄3 cup maple syrup
• 5  tablespoons  whole milk
• 1  teaspoon vanilla extract
• 1  teaspoon  maple extract (optional)
•  granulated sugar, for sprinkling (optional)

Directions

1. Pulse walnuts in food processor until finely ground; you should have 1/2 cup. Add flours, brown sugar, baking soda and salt, and pulse to combine. Add butter and pulse in 1-second bursts until it resembles wet sand, 8-10 pulses.
2. Whisk together maple syrup, milk, vanilla extract, and maple extract (if using) in small bowl. Add to food processor and pulse just until dough comes together, 3-5 pulses. It will be very soft and sticky. Scoop dough onto a large sheet of plastic wrap. Pat it into a 1-inch thick rectangle. Wrap tightly in plastic and chill in the refrigerator for at least two hours, or up to overnight.
3. Preheat oven to 350°F Line two baking sheets with parchment paper. Dough will remain soft and fairly sticky, so flour board and rolling pin generously. Divide dough in half; return one piece to refrigerator. Roll into a 12x8 sheet; trim the edges neatly with a pizza cutter, then cut into 12 4x2 rectangles. Transfer rectangles to lined sheet pan. Using tines of a fork, poke 5 rows of holes down the center of each cracker, then turn fork over and crimp the edges of each cracker. Place pan in refrigerator while preparing the remaining piece of dough. When second pan is ready, keep both in refrigerator for 30 minutes.
4. Sprinkle crackers with granulated sugar, if using, then bake in preheated oven until edges are lightly browned and crackers are firm to the touch, about 15 minutes. Spin each sheet 180° and swap racks halfway through. Cool on pan 2-3 minutes, then transfer to a rack until completely cooled. Store in airtight container for up to one week.