In a small bowl, stir the yeast into 3/4 cup warm water and set aside until foamy, about 5–10 minutes.
In the bowl of a stand mixer fitted with the dough hook, combine the bread flour, sugar, salt, and dry milk powder.
Add the vegetable oil and 1¼ cups water to the dry ingredients and mix on low for 3 minutes to hydrate the flour.
Add the yeast mixture and knead on medium speed with the dough hook for about 8 minutes, until the dough is smooth and elastic.
Loosely cover the bowl and let the dough rise in a warm place until doubled in size, about 45 minutes.
Punch the dough down and divide it into 24 equal pieces. Lightly spray a 9x13-inch baking dish and place the rolls seam-side down in the dish.
Loosely cover the baking dish and let the rolls rise in a warm spot until doubled, about 30 minutes.
Preheat the oven to 400°F (200°C). Bake the rolls for 18 to 20 minutes, until golden brown on top.
Brush the warm rolls with melted butter, if desired, and serve.