From The 4-Phase Histamine Reset Plan, by Dr. Becky Campbell.

1/3 cup (48 g) maple sugar
1 tsp preservative-free vanilla
3/4 cup (92 g) cassava flour; I prefer Otto’s because it’s the only unfermented brand
1 tsp coarsely chopped fresh rosemary
1 tsp grated lemon zest
1/2 cup (115 g) cold salted grass-fed butter, cut into chunks

• Preheat the oven to 325F (163C). Grease a 9-inch (23-cm) round pie pan. I occasionally make a double-batch on cookie sheet, instead.
• Place the sugar, vanilla, flour, rosemary, and butter into a food processor and pulse for about 10 seconds, or just until everything is combined.
• Remove the dough from the processor and form it into a ball, making sure everything is sticking together well and that it is not flaky.
• Place the dough into the prepared pie pan and press it into a thin layer.
• Bake for 30 minutes, or until the shortbread is golden on the edges.
• Let the shortbread cool for 5 minutes before cutting.

A batch of these cookies is 137 grams of carbohydrates, a double batch is 274 grams. I divide the cookie sheet into ~36 cookies, which are about 8 grams of carbs per cookie.