Cut the butter into small cubes, about 1/2”, and allow to soften at room temperature. Let the eggs and milk come to room temperature as well.
Add a teaspoon of sugar to the room temperature milk, mix to dissolve. Sprinkle the active dry yeast over the milk and stir to submerge all the yeast. Let it bloom for about 10 - 15 minutes; the mixture should puff up.
Meanwhile, add the rest of the sugar, flour and salt in a small bowl and whisk to evenly distribute.
In the bowl of your stand mixer, lightly beat the eggs with a hand whisk. Add the bloomed yeast mixture along with the flour mixture to it. Use the dough hook to knead on low speed (speed 2) for 5 minutes until a wet dough comes together.
Leave the mixer on speed 2 and add the soften butter, a few pieces at a time, allowing it to combine with the dough before adding more. This will take about 10 - 15 minutes. Then let the mixer knead for another 10 - 15 minutes until all of the butter is completely incorporated.
Scrape the dough out onto a floured counter top, sprinkle flour on top of the dough. Rub butter or oil on your hands and knead a few times until smooth and shape the dough into a ball.
Place dough into an oiled glass bowl and let rise in a warm spot for 1.5 - 2 hour until at least double in size.