Combine all the ingredients for the sponge in a medium bowl and mix with your hands. You can mix with a spoon, but it will be more difficult because the mixture is so wet.

Cover with plastic wrap and set in a warm spot until visibly bubbly, about 20 minutes.

Add the flour, remaining sugar, salt, butter, egg, and sponge to the bowl of a stand mixer. Mix on low speed with the paddle attachment until combined.

Switch to the dough hook and mix on medium speed until a rough window pane can be pulled. This can take 10- 15 minutes. It is an enriched dough, meaning the gluten will develop slower.

Scrape the dough into a well-oiled bowl, cover with plastic wrap or a kitchen towel, and allow it to proof for 30 minutes in a warm place.

Fold the dough by grabbing one side, pulling it upwards out of the bowl, and then folding it over ⅓ of the dough. Rotate the bowl 180 degrees and repeat with the opposite side. Rotate a quarter turn and repeat the same folding technique. Rotate the bowl 180 degrees and make the final fold. You should have a nice, tight square packet of dough. Cover with plastic wrap and allow to double in a warm place. Mine took about an additional 30 minutes.

While the dough is finishing its bulk proofing, grease a 9 x 13-inch baking dish with cooking spray or butter.

When the dough has doubled and feels light and airy when touched, turn it out onto an unfloured surface. The dough is soft, supple, and not sticky!

Divide into 12 equal portions. You can eyeball or weigh them.

Take a portion and fold it in half, and then place the seam side down on the counter. Roll in the palm of your hand into a ball and shape each into boules, using your thumb as a guide. Place each roll equidistant apart in the prepared baking pan.

Cover and place back in the warm spot to double. This took about 30 minutes for me. Preheat the oven to 350°F.

When the buns are ready to bake (doubled and light and airy), brush with beaten egg.

Bake in the preheated oven for 20-22 minutes until golden brown or until an instant-read thermometer reads 185°F when inserted into the center of one of the middle buns. If you don’t have a thermometer, you can insert a cake tester or toothpick into the center, and it should come out with clinging crumbs but no streaks of dough!

Brush the hot buns with melted butter to emulate my shiny, enticing tops! Technically, they should cool, but who has the patience? I say dig right in.