* All purpose and pastry flour can be replaced with gluten free flour of choice, and 1/2 to 1 tsp xanthan gum.
Instructions
In a medium bowl, whisk together butter, vanilla and egg until combined.
Whisk in salt, baking powder and sugar.
Stir in both flours, and nuts. Dough should be quite firm, but still somewhat sticky.
Preheat oven to 350°F. Line a baking sheet with parchment paper.
On the prepared baking sheet, form the dough into a rectangle about 12 inches long, 4 inches wide, and 1/2 inch thick.
Bake in the preheated oven for about 20 minutes, until firm to the touch, but not very brown. Cool on a baking rack for about 20 minutes, until nearly room temperature.
While the dough is cooling, drop the oven temperature to 300°F.
Using a serrated knife, cut the rectangle across its width into strips about 1/2 inch wide. Place the strips on an oven-safe cooking rack and return to the oven. Bake for an additional 20 – 30 minutes, until crisp and lightly browned.
Store in an airtight container at room temperature for up to 2 weeks, or in the freezer forever (6 months).