Step 1

In a large bowl, whisk together flour, water, sourdough starter, milk powder, butter, sugar, salt, and yeast until smooth. Cover with plastic wrap and let stand at room temperature until batter has roughly doubled in volume, about 1 hour.

Step 2

Heat griddle on medium heat (see note). Spray the inside of eight 3 1/2-inch English muffin rings or round ring molds with non-stick cooking spray and place on griddle. Without stirring the batter, use a 1/3 measuring cup to evenly portion it into the rings. Cover rings with a baking sheet, reduce heat to low, and cook undisturbed for 5 minutes.

Step 3

Remove baking sheet. Using tongs to hold rings in place, slide a spatula underneath muffins and flip over to cook other side. Cover again, and cook 5 minutes longer.

Step 4

Remove baking sheet. Using tongs, remove rings from muffins and set aside. Using a spatula, transfer muffins to a wire rack to cool for about 10 minutes. Split English muffins by hand or with a fork. If desired, toast before serving.