Put the flour into a large mixing bowl and whisk in the salt and dill. Beat in the 4 tablespoons of room‑temperature butter until the flour resembles cornmeal in texture. Beat in the yogurt until the mixture forms a thick dough. Cover the bowl tightly and allow it to rest in a warm place in your kitchen for at least 8 and up to 12 hours.
Position racks in the upper and lower thirds of the oven and preheat the oven to 450°F. Line two baking sheets with parchment paper.
Divide the dough into four portions. Flour your work surface and roll out each piece of dough to an even 1/16-inch thickness, then use a pizza cutter or sharp knife to cut the dough into 1 1/2-inch squares. Place the squares on the prepared baking sheets, spacing them about 1/2 inch apart.
Brush the squares with the 2 tablespoons of melted butter and prick them with the tines of a fork to prevent them from puffing as they bake. Bake for 6 to 8 minutes, until the crackers are just tinged with gold around their edges. Pull them from the oven and cool them on a wire rack. Store the crackers in an airtight container for up to 2 weeks.
Reprinted with permission from The Nourished Kitchen by Jennifer McGruther, (c) 2014. Published by Ten Speed Press, a division of Random House, Inc. Photography (c) 2014 by Jennifer McGruther