In a large mixing bowl, combine the buckwheat flour, ground sunflower seeds, sesame seeds, nutritional yeast, baking powder, sea salt, dried rosemary, dried thyme, and garlic powder. Whisk thoroughly so all dry ingredients are evenly distributed.

Drizzle in the olive oil (use 2 tablespoons for a lighter cracker or 3 tablespoons for extra richness). Use your fingertips to rub the oil into the flour mixture until it resembles fine crumbs.

Gradually add warm water, starting with 1 tablespoon. Mix with your hands until a cohesive dough forms. It should be pliable—neither sticky nor dry and crumbly. If too dry, add a few drops of water; if too sticky, dust with a small pinch of extra buckwheat flour.

Preheat oven to 350°F (175°C) fan-forced / 380°F (195°C) conventional

Transfer the dough ball onto a large sheet of parchment paper. Flatten slightly with your hand, cover with a second piece of parchment paper, and roll into an ultra-thin sheet (about 2 mm / 0.08" thick). Tip: Check the center of your sheet—it tends to stay thicker than the edges.

Peel off the top sheet of parchment paper. Using a pizza cutter or sharp knife, score the dough into equal squares or rectangles. Transfer the bottom parchment sheet with scored dough onto a baking sheet.

Bake until light golden and crisp. The outer edges will crisp up faster (around 15–17 minutes)—carefully remove edge pieces if needed, spread the middle pieces slightly, and return the center crackers to the oven for a few extra minutes until fully crisp.

Store fully cooled crackers in an airtight container for up to 1 week.