1. Mix tapioca flour, brown rice flour, white rice flour, sugar, xanthan gum, and 1/2 teaspoon salt in the bowl of a stand mixer set with the whisk attachment; cut in butter using the whisk setting, starting on low and working up to medium, stopping occasionally to scrape down the sides and bottoms, until mixture resembles coarse crumbs.

2. Slowly pour milk into butter-flour mixture while mixer is on low. Gradually increase speed and mix until batter is well mixed. Cover bowl and let dough sit for 15 minutes.

3. Preheat oven to 325 degrees F (165 degrees C). Spray 2 pieces parchment paper with cooking spray.

4. Roll dough on 1 of the sprayed sheets parchment paper. Top with the other parchment sheet, spray-side down, and roll dough to 1/8-inch thickness. Remove the top sheet and pat any edges back toward the middle if they are thinner than the rest to prevent burnt edges on the crackers.

5. Cut dough into cracker shapes using a pizza cutter and prick each square with a fork. Place parchment paper with crackers on a baking sheet and place on the middle rack in the oven.

6. Bake in the preheated oven for 3 minutes. Sprinkle sea salt over crackers; continue baking until crackers are browned and crisp, 18 to 25 minutes. Cool on the baking sheet or transfer crackers to a wire rack.

Cook's Notes:

I like to keep butter on the counter in a butter bell. This gives me instant access to soft butter for meals or baking.

Also, I would guess these would freeze just fine, but I've never had any around long enough to freeze them and I don't have an air vac system to test out that storage method.

If you have Expandex(R) tapioca flour, you may want to try that in place of the tapioca flour, but I don't have access to that up here in Alaska.

The dough can be placed in the refrigerator after mixed in Step 2. Just take it out 15 minutes before using so it can warm to room temperature.