In a small bowl, mix the warm water, yeast, and sugar. Stir gently and let sit for 5–10 minutes until foamy.
In a large mixing bowl (or the bowl of a stand mixer fitted with a dough hook), combine the yeast mixture, buttermilk, melted butter, and salt. Gradually add the flour, 1 cup at a time, mixing until a soft dough forms. The reason I say 1 cup at a time is that if you live in a different climate or altitude than I do, you might need just a tad less flour than me, and that's completely fine!
Knead the dough by hand on a lightly floured surface for 8–10 minutes, or use the stand mixer on medium speed; the dough should be smooth and elastic.
Transfer the dough to a lightly floured bowl, cover it with plastic wrap or a kitchen towel, and let it rise in a warm spot for 1–1.5 hours, or until doubled in size.
Punch down the risen dough and divide it into 10-12 equal pieces - mine each weighed around 110 grams . Roll each piece into a smooth ball and arrange them in a greased 9x13-inch baking dish or two smaller circular pans (depending on how you'd like them to be presented) , leaving a little space between each roll. ( if you'd like to make 20-24 rolls, weigh each dough ball to be roughly 55g each)
Cover the rolls loosely and let them rise for another 30 minutes, or until puffy and touching.
Preheat your oven to 375°F (190°C) while your doing is doing its second rise.
In a small bowl mix the melted butter, garlic powder, and salt for the garlic butter mixture
In a separate small bowl, whisk together the egg, buttermilk, and 1 tbsp of the garlic butter mixture. Lightly brush the tops of the rolls with the egg wash.
Bake the rolls in the preheated oven for 22-25 minutes, or until golden brown and baked through.
As soon as the rolls come out of the oven, generously brush them with the garlic butter. Let them cool for 10 minutes.
Serve warm with a little extra garlic butter on the side, if desired.