04Continue kneading on medium-high speed for 4 to 5 minutes until a soft, smooth ball of dough is formed. The dough ball should feel elastic and slightly tacky to the touch.
05Lightly spray a large bowl with cooking spray and place the dough in the bowl. Cover the bowl lightly with plastic wrap or a kitchen towel.
06Let dough rise for about 1 hour to 90 minutes at room temperature or until the dough is big, puffy, and about doubled in size.
07Grease a 9×13-inch or similarly shaped baking pan with butter. Gently deflate the dough.
08Use a bench scraper, knife, or pizza wheel to divide the dough into 12 equal pieces. Shape each piece into a ball and place it in the prepared pan.
09Lightly cover the dough with plastic wrap and let the rolls rise for about 1 hour, or until about doubled in size.
10Preheat the oven to 375°F.
11Brush the rolls gently with the beaten egg. Bake for 20 minutes or until golden brown.
12Brush with melted butter and sprinkle with flaky salt. Serve warm. Store leftovers in an airtight container or zip-top bag for up to 3 days.