Ingredients

• 2 cups (285 grams) bread flour
• 1 cup (142 grams) whole-wheat flour
• 2 3/4 teaspoons kosher salt, preferably Diamond Crystal (may substitute half as much table salt by volume)
• 1 1/4 teaspoons instant yeast (not rapid-rise)
• 1 1/2 cups (355 milliliters) cold milk (any percentage)
• 1/4 cup (100 grams) honey
• 1 large egg white, cold
• 1 cup (142 grams) fine cornmeal, for dusting
• 2 tablespoons (30 grams) unsalted butter, bacon fat or oil, plus more as needed

Directions

In a large bowl, whisk together the bread flour, whole wheat flour, kosher salt and yeast until well combined. Add the milk, honey and egg white, stirring with a flexible spatula until smooth, about 5 minutes. The dough will be fairly wet but elastic, and will start to come together into a ball. Cover the bowl with plastic wrap or a plate (or transfer to a lidded container) and set aside at room temperature (70 degrees) for 4 to 5 hours, until the dough is spongy, light and has more than doubled in size. (The timing is flexible depending on your schedule.)

Generously cover a large, rimmed baking sheet with an even layer of cornmeal (you may use about half to three-quarters of it). With a large spoon, dollop out a dozen 2 2/3-ounce (75 grams) portions of dough; it’s perfectly fine to do this by eye. If you’d like, pinch the irregular blobs with slightly dampened fingers to tidy their shape. Sprinkle with additional cornmeal, cover with plastic wrap, and refrigerate for 12 to 48 hours.

Heat a 12-inch cast-iron skillet or griddle over medium-low heat. (If you have an electric griddle, preheat it to 325 degrees.) When it’s sizzling-hot (check by sprinkling a few small drops of water), add half the butter and melt. Griddle the muffins until their bottoms are golden brown, about 8 minutes, rotating each muffin 180 degrees halfway through so the outer edges are moved to the center for even browning. Flip with a square-end spatula and griddle until the other side is golden brown as well. Depending on the size of your skillet or griddle, you may have to cook the muffins in batches, adding 1/2 to 1 tablespoon of butter to the skillet each time. Transfer the muffins to a wire rack until cool enough to handle, then split the muffins by working your thumbs around the edges to pull them open a little at a time. Toast before serving.