In the bowl of a stand mixer fitted with the dough hook attachment, combine flour, instant yeast, warm water, sugar, salt, cubed butter, and one egg. Mix on low speed until all ingredients are incorporated with only a few pieces of butter remaining. Room temperature butter will incorporate faster, but it isn't necessary.

Increase mixer to medium speed and knead for 5-6 minutes, or until the dough pulls a smooth windowpane. The dough is sticky but soft and easy to work with. You can use oiled or lightly floured hands if needed.

Scrape dough into a large bowl sprayed with non-stick cooking spray or lightly coated with neutral oil. Cover and proof in a warm spot for 45 minutes to an hour, or until visibly doubled and airy to the touch.

Spray a 9x13-inch baking dish with non-stick cooking spray or grease with softened butter.

Turn the dough out onto a lightly floured work surface and divide into 12 pieces (approximately 80g each).

Shape each piece into a roll by folding each edge into the center, flipping seam-side down, and rolling quickly between your thumb and other fingers. Use a push-pull motion to create surface tension and form a smooth ball. The key is to work quickly so the dough doesn't stick excessively to your hands or counter. Allowing it to stick slightly to the counter will actually help create tension. Flour your hands as needed.

Place shaped rolls in the baking dish and repeat with remaining dough. Cover with plastic wrap and proof in a warm spot for 1 hour, until tripled in size and light and airy when gently touched. Meanwhile, preheat the oven to 350°F conventional (no fan).

Before baking, gently brush the tops with beaten egg (egg wash). Be gentle and don't let it run down the sides of the dish or pool, as this will prevent proper browning.

Bake rolls in preheated oven for 25-28 minutes until golden brown. You can also test with an instant-read thermometer — this enriched dough should read 185°F.

Serve slightly warm or at room temperature. Brush with melted butter if desired.