Start preheating the oven to 400F/200C.In the bowl of a food processor combine the buckwheat flour, xanthan gum, baking powder, salt, and sugar. Pulse a couple of times to incorporate.Then cube cold butter (into about 1in/2cm cubes) and add it to the dry ingredients. Pulse until the mixture resembles coarse sand (a couple minutes).

Then add the oil and water to the bowl of the food processor and pulse until the dough comes together (a few minutes).

Transfer the dough onto a lightly floured working surface and roll it out about ⅛in/3mm thin.Oil the surface of the dough if it keeps sticking to the rolling pin.

Cut out the cracker shapes with a cookie cutter about 2in/6cm in diameter.You can use a round cookie cutter or cut the dough into strips with a pizza cutter. Transfer the crackers onto a baking sheet lined with parchment paper, then poke little holes using a toothpick or a fork. Bake at 400F/200C for 10-12 minutes until the crackers look golden brown on the edges. If they aren't golden, they won't be crunchy! Brush the crackers with melted butter right when you take them out of the oven for a better flavor and texture. Reroll the dough and repeat. Enjoy!