The next morning, turn your dough out (gently) onto a floured surface. Gently pat it down (be careful not to degas it) until it is 1 inch (2.5cm) thick.
Prepare 2 baking sheets with parchment paper, and sprinkle on your cornmeal.
Using a 2 3/4 inch (7cm) round biscuit cutter, cut out rounds from your dough, and place them on your parchment. To use up your scrap dough, you can push the dough together and pinch to seal gently, and then cut out more muffins. The scrap muffins may look less beautiful, but they will still bake up delicious!
Cover your muffins with a tea towel, and allow them to rise 1-2 hours at room temperature. They will grow even more when you bake them (see video for reference).
Preheat your cast iron skillet at the lowest heat for at least 10 minutes.
Place 4 muffins in your pan, cover, and bake for 4 minutes.
Turn your muffins over, cover, and bake 4 additional minutes. The muffins should be 205 deg F (96 deg C) at their center when done.
Set the muffins on a cooling rack to cool.
Cut, serve with butter, jam, or as a sandwich or eggs benedict, and enjoy!
If freezing: wait until the muffins have cooled completely, then place them in an airtight container, and freeze. When ready to use, you can let them thaw on the counter, or pop them in the microwave for 20 seconds, before cutting and toasting as you would normally.