Combine flours, vegan cheese, butter, garlic powder, turmeric, nutritional yeast, and salt in a bowl. Microwave in 20-second increments until the vegan butter melts and the cheese softens (usually around 1 minute).
Stir the batter together, then add a tablespoon of water (one at a time) and stir to create a cohesive batter. Add only enough water for the batter to form.
Spray a piece of parchment paper with cooking spray. Lay it on the counter, sprayed side up. Place the dough in the center of the paper. Spray another sheet of paper and lay it sprayed side down on top of the dough.
Use a rolling pin to press the dough to flatten it. Remove the top sheet of parchment paper and use a spatula to even out the sides of the dough. Place the parchment paper back on top and roll again, until the dough is a thin layer. (Thick crackers will be less crunchy but too thin will be too crunchy. You're looking for a nice balance between the two.)
Cut the dough into 1-inch (or slightly less than 1-inch) strips. Turn the paper and cut parallel lines to create squares.
Use a chopstick to create a divot in the center of each cracker. Transfer the parchment sheet to a baking sheet and bake for 7 to 8 minutes.
Remove them from the oven and use a pizza cutter to run along the previous cuts. This will separate the crackers. Return the pan to the oven and bake for another 5 minutes, until the crackers are golden brown on the edges.
Allow the crackers to cool completely so they'll become crispy.