Instructions

• Warm the 2/3 cup whole milk to about 110°F (warm to the touch, not hot). Sprinkle the 2 1/2 teaspoons active dry yeast into the milk, stir to combine, and let stand until foamy, about 5 minutes.
• In a large mixing bowl, whisk together 4 1/4 cups all-purpose flour, 1/2 cup granulated sugar, and 3/4 teaspoon salt.
• Add the 1/2 cup melted unsalted butter, the 3 large eggs, and the foamy yeast-milk mixture to the dry ingredients. Mix until a soft, shaggy dough forms.
• Turn the dough onto a lightly floured surface and knead until smooth and elastic, about 8–10 minutes by hand (or 5–7 minutes in a stand mixer with a dough hook).
• Place the kneaded dough in a lightly greased bowl, cover with plastic wrap or a clean towel, and let rise in a warm place until doubled in size, about 1 1/2 to 2 hours.
• While the dough rises, make the topping: in a medium bowl, beat together 1 cup all-purpose flour, 2/3 cup powdered sugar, 1/2 cup unsalted butter (room temperature), and 1 1/2 teaspoons vanilla extract until a smooth, spreadable paste forms. If using food coloring, divide a portion of the topping and mix in color as desired. Divide the topping into 12 equal pieces.
• After the dough has doubled, punch it down gently, divide it into 12 equal pieces, and shape each piece into a smooth ball. Place the dough balls on a baking sheet lined with parchment, leaving space between them.
• Flatten each topping piece into a thin circle large enough to cover the top of a dough ball (use your hands or roll between parchment). Drape a topping circle over each dough ball and lightly press to adhere. Use a sharp knife to score the topping with a clamshell or other design, taking care not to cut into the dough.
• Preheat the oven to 350°F. While the oven preheats, cover the prepared buns loosely and let them rest for about 15 minutes. Bake the buns at 350°F for 18–20 minutes, until the buns are set and the topping is lightly golden. Transfer to a wire rack to cool.