The Bojon Gourmet

Make the dough
0 In the bowl of a food processor (or in a large bowl), combine the sweet rice flour, teff flour, oat flour, cornstarch, light brown sugar, cinnamon, baking powder, baking soda, and salt.
6 Scatter the butter pieces over the top and pulse in (or rub with your fingertips) until the butter is incorporated and the mixture resembles the texture of polenta. 
7 Drizzle the water, honey, and vanilla over the flour mixture and pulse (or toss with a flexible spatula or your hands) until the dough just comes together, adding more water a few drops at a time if needed.
1 Knead the dough lightly in the bowl and gather it into ball. Flatten the dough ball into a disk and wrap in beeswax wrap or plastic wrap. Chill until firm, 20-30 minutes.
Shape
2 On a piece of parchment paper dusted with oat flour, roll the dough into a rectangle to about ⅛-inch thick; it will be roughly 14 by 11 inches. As you work, when the dough begins sticking to the parchment, dust the top with more oat flour, sweep the excess away with a dry pastry brush, place a second piece of parchment on top, flip the whole thing over, and peel away the parchment. Dust the top with more flour and continue rolling.
3 Slide the dough, parchment and all, onto a rimless cookie sheet. Use a sharp chef’s knife or pastry cutter to cut the dough into squares or rectangles. Leave the graham crackers where they are and prick them all over with a fork. 
13 Chill until firm, 20 minutes.
Bake
4 Position a rack in the upper third of the oven and preheat to 325º F.
5 Sprinkle the cookies with the coarse sugar and bake until deep golden brown and fairly firm to the touch, 15-22 minutes. 
12 Cut the graham crackers again with a knife and let them cool. If they aren’t fully crisp when cool, put them back in a low oven to further dry them out. 
14 Store airtight at room temperature for up to 2 weeks.