Step 1

Combine yeast and sugar in a medium bowl (or in the bowl of a stand mixer) and add 1 cup warm water; stir to dissolve yeast. Let rest until foamy, about 5 minutes.

Step 2

Add milk powder, salt, and 3 cups flour and mix with a wooden spoon (or beat with a dough hook if using stand mixer) until no dry spots remain. Mix in ½ cup more flour and 4 Tbsp. softened butter a few pieces at a time, adding more flour if needed to incorporate butter, until a soft dough forms.

Step 3

Turn dough out onto a lightly floured work surface. Knead until smooth and elastic, adding more flour if needed to keep dough from becoming too sticky, 10–15 minutes (alternatively, knead with dough hook in stand mixer on medium speed 8–10 minutes). Form dough into a ball, rolling and tucking edges underneath. Lightly brush a medium bowl with melted butter. Place dough in bowl and lightly brush with melted butter. Cover with plastic wrap and let rise in a warm, draft-free spot until almost doubled in size, about 1 hour.

Step 4

Lightly butter a 9x5" loaf pan. Gently punch down dough then turn out onto a lightly floured work surface and gently roll out to a 9" log. Pinch seam to close, then place log, seam side down, in prepared pan and cover lightly with plastic wrap. Let rest until dough rises about 1" above rim, 60–75 minutes.

Step 5

Preheat oven to 350°. Using a sharp knife, score loaf lengthwise down the center of the top, about ½" deep, if desired. Brush with any remaining melted butter. Bake bread until deep golden brown and sounds hollow when tapped with your fingertips, 50–60 minutes. Let cool in pan on a wire rack at least 30 minutes before turning out and slicing.

Step 6

Do Ahead: Bread can be kept tightly wrapped at room temperature for 3 days or frozen for up to 1 month; cool completely before storing.