Whisk the warm water, warm milk, yeast, and sugar together in the bowl of a stand mixer fitted with the dough hook, then cover and let the mixture stand for 5 minutes. The surface should look foamy or creamy, and it should smell lightly sweet and bready rather than flat or harsh.

Add the butter, salt, and 1 cup flour, mix on low speed for 30 seconds, scrape the bowl, add another cup of flour, then mix on medium until partly combined before adding the remaining flour and mixing about 2 minutes more until a dough forms. At this stage the dough should start pulling away from the sides of the bowl, and a few small butter pieces are fine before everything smooths out.

Knead the dough for 5 to 8 minutes in the mixer, or turn it onto a lightly floured surface and knead by hand for 5 to 8 minutes, adding flour only 1 teaspoon at a time if it becomes too sticky. The dough should feel soft and supple, almost like an earlobe, and it should stay slightly tacky rather than dry.

Lightly grease a large bowl with olive oil or nonstick spray, place the dough inside, turn it to coat, cover, and let it rise in a relatively warm spot for 1 to 2 hours until doubled in size. When it’s ready, the dough will look puffed and airy, and a gentle poke will slowly spring back.

Grease a 9×5-inch loaf pan, gently press down the risen dough, then roll it on a lightly floured surface into an 8×15-inch rectangle and roll it up into an 8 inch log before placing it in the pan. Try to roll it snugly so there are no large gaps, because tight shaping helps the loaf rise taller and slice more evenly.

Cover the shaped loaf with aluminum foil, plastic wrap, or a clean kitchen towel and let it rise for about 1 hour until the dough sits about 1 inch above the rim of the pan. The dough should look rounded and airy, and it should hold a soft indentation when touched lightly.

Set an oven rack in a lower position and preheat the oven to 350°F (177°C). Baking lower in the oven helps the top brown more evenly instead of darkening too fast.

Bake the loaf for 32 to 36 minutes, tenting loosely with foil if the top is browning too quickly. The bread is ready when the top is golden brown and the loaf sounds hollow when tapped.

Cool the bread for a few minutes in the pan on a rack, then remove it from the pan and let it cool before slicing. If you cut it too early, the crumb can turn gummy instead of soft and fluffy.