In a mixing bowl, combine the active sourdough starter with lukewarm water. Whisk until smooth.

Add both flours to the mixture, followed by salt and sugar. Mix until combined to form a shaggy dough.

Use a dough scraper to knead the dough gently for about 5-7 minutes, until it becomes smooth and elastic.

Place the dough into a lightly greased bowl, cover with a damp cloth, and let it rest at room temperature for about 4 hours or until doubled in size.

After the dough has risen, turn it out onto a floured surface. Flatten it gently with your hands to about 1-inch thickness.

Use a round cutter (preferably 3-4 inches) to cut out muffins and place them on a baking sheet lined with parchment paper.

Dust the tops of the muffins with cornmeal to prevent sticking. Cover lightly with a cloth and allow them to proof for another 2 hours.

Preheat your cast iron skillet or griddle over low to medium heat. Cook the muffins for about 7-8 minutes on each side until they are golden brown.

Remove the muffins from the skillet and let them cool on a wire rack.

Store them in an airtight container and enjoy toasted, with butter, or your topping of choice.