In a mixing bowl, combine the fed sourdough starter and warm water.

Gradually add the all-purpose flour, granulated sugar, unsalted butter, egg, and salt to the mixture, stirring until a dough forms.

Knead the dough on a floured surface until smooth.

Place the dough in a greased bowl, cover it, and let it rise until doubled in size, about 2-3 hours.

Once risen, shape the dough into balls and dust each with cornmeal.

Preheat a skillet over medium heat.

Cook the muffins in the skillet for 5-7 minutes on each side, until golden brown.

Allow the muffins to cool before slicing.