Melt the butter and measure out 1/4 cup plus 2 tablespoons, keeping them together for now. Heat 1 1/4 cups milk in a small saucepan until steaming and tiny bubbles form around the edges.
Pour the hot milk into the bowl of a stand mixer fitted with the dough hook. Add 1/4 cup water, 6 tablespoons granulated sugar (81 grams), and 1/4 cup of the melted butter. Let the mixture cool until warm to the touch (like a warm bath).
Stir in 2 1/4 teaspoons instant or active dry yeast and let it sit 5 to 7 minutes, until foamy.
Add 1 large egg, 1 teaspoon salt, and 4 1/4 cups bread flour to the mixer. Start mixing on low speed, then gradually add up to 4 1/2 cups bread flour as needed until the dough pulls away from the sides of the bowl and forms a soft, slightly sticky ball. Do not add more than 4 1/2 cups flour.
Continue kneading the dough on low speed for 5 to 6 minutes, until it is smooth and elastic.
Shape the dough into a ball, cover the bowl with plastic wrap or a clean kitchen towel, and let it rise in a warm, draft-free spot until doubled in size, about 1 hour.
Punch down the dough and divide it into 12 equal pieces. Gently shape each piece into a roughly square roll and place them on a rimmed baking sheet lined with a silicone mat or parchment paper, arranging them so they will touch as they rise.
Cover the rolls and let them rise again until very puffy and touching one another, about 45 to 60 minutes.
While the rolls are finishing their second rise, preheat the oven to 375°F and position a rack in the center.
When the oven reaches temperature, bake the rolls for 15 to 20 minutes, until golden brown on top and bottom.
Remove the rolls from the oven and immediately brush the tops with the remaining 2 tablespoons melted butter. Serve warm.