In the bowl of a stand mixer fitted with the dough hook, mix the flour, yeast, sugar, salt, butter, milk, and egg together on low speed until a dough starts to form. Increase the speed to medium and mix for 7-8 minutes until the dough is smooth and no longer sticking to the sides of the bowl.
3½ cups all-purpose flour, 2½ teaspoons instant yeast, 3 tablespoons granulated sugar, 1¼ teaspoons kosher salt, 3 tablespoons unsalted butter, 1 cup whole milk, 1 large egg
Transfer the dough to a large oiled bowl, cover loosely with plastic wrap, and let rise for 90 minutes in a warm location.
Brush a 9x13-inch baking dish with melted butter. Set aside.
Punch the dough down and roll it into an 8x12 inch rectangle. Brush the top with melted butter.
Cut the dough into 8 even rectangles by cutting 4 horizontal rows and once vertically down the center.
Fold each rectangle over itself, so that the butter is hidden, with a ¼ inch overhang. Place in your baking sheet and repeat with the second half of the dough.
Cover loosely with plastic wrap and let rise for 45-60 minutes in a warm location until puffy. While the rolls are rising, preheat the oven to 350 degrees.
Bake the rolls for 20-25 minutes or until golden. Remove from the oven and brush with the remaining melted butter. To make honey butter, mix the 4 tablespoons butter with the honey. Top with flaky salt. Serve immediately.
4 tablespoons unsalted butter, 2 tablespoons honey, ½ teaspoon flaky sea salt