Preheat the oven to 350°F (175°C). Line 2 large baking sheets with parchment paper or silicone baking mats to prevent sticking and help the crackers crisp evenly.
In a medium bowl, whisk together the white rice flour, brown rice flour, cornstarch or potato starch, fine sea salt, sugar, and any optional dry seasonings you are using until well combined and free of lumps.
1 1/2 cups white rice flour, 1/2 cup brown rice flour, 2 tablespoons cornstarch or potato starch, 1/2 teaspoon fine sea salt, 2 teaspoons sugar, optional seasonings
Add the neutral oil, soy sauce or tamari, and toasted sesame oil to the dry ingredients. Stir with a fork or spatula until the mixture looks sandy and evenly moistened.
3 tablespoons neutral oil, 2–3 tablespoons low-sodium soy sauce or tamari, 1 teaspoon toasted sesame oil
Pour in 1/2 cup hot water and stir until a soft, slightly tacky dough forms. If the dough is too dry or crumbly, add more hot water 1 tablespoon at a time. If it becomes too wet, sprinkle in a little more rice flour. The dough should feel like pliable playdough and hold together without being sticky.
1/2 cup hot water
Gently fold in the sesame seeds, if using, just until evenly distributed throughout the dough without overworking it.
2–3 tablespoons sesame seeds
Divide the dough into two equal portions. Place one portion between two sheets of parchment paper and roll it out very thin, about 1/16 to 1/8 inch thick, aiming for an even thickness for the crispiest texture. Repeat with the second portion.
Peel off the top piece of parchment. Use a small round cookie cutter, knife, or pizza cutter to cut the dough into small rounds, squares, or rectangles. Transfer the pieces to the prepared baking sheets, leaving a little space between each cracker. Gather and re-roll scraps once or twice as needed.
Lightly brush or spray the tops of the crackers with neutral oil or cooking spray. If desired, sprinkle a little extra fine sea salt, sesame seeds, or furikake over the tops for added flavor and texture.
neutral oil or cooking spray, extra fine sea salt, sesame seeds, or furikake
Bake the crackers at 350°F (175°C) for 14–18 minutes, rotating the baking sheets halfway through. The crackers are done when the edges are lightly golden, the surface is dry and firm, and they have a crisp snap when tapped. Begin checking at 12 minutes, especially if your crackers are very thin or small.
Remove the baking sheets from the oven and let the crackers cool completely on the pans; they will crisp further as they cool. If any crackers in the center are still slightly soft once cooled, return the tray to the oven for 2–3 minutes more, then cool again.
Serve the rice crackers on their own or with cheese, dips, or tea. Once fully cooled, store in an airtight container at room temperature for up to 7–10 days.