In a food processor, pulse the walnuts with 2 tablespoons of the sugar until finely ground. Transfer to the bowl of a standing electric mixer fitted with a paddle. Add the remaining 1/2 cup sugar and the flour, cornmeal, baking powder, and salt. Mix on low speed until combined. Add the butter and mix until a coarse meal forms. Add the egg and maple syrup and mix until combined.
Divide the dough in half. Roll out each piece to a 7-inch log, about 1 1/2 inches thick. Wrap each piece in plastic and refrigerate for at least 2 hours or overnight.
Preheat the oven to 350°. Slice each log 1/3 inch thick. Using your hands, roll each slice out to an 8-inch stick and arrange them about 1 inch apart on 2 nonstick baking sheets. Twist and turn one end of each cookie to make a little squiggle. Bake the cookies for about 18 minutes, or until browned and crisp. Let cool on the baking sheet before serving.