Combine yeast and 1 tsp. sugar in small bowl. Add warmed water, stir until yeast is dissolved and let it sit until it begins to form bubbles.
In large bowl or bowl of a stand mixer, combine ½ c. softened butter, remaining sugar and salt.
Using stir setting on mixer or using a wooden spoon, add yeast mixture, warmed milk and beaten eggs.
Slowly add in 2 cups of flour; stir 2 minutes or until smooth. Add in remaining 2 and ½ cups of flour, 1 cup a time until a soft dough is formed. The dough will be slightly sticky; add additional ½ cup of flour if dough is sticking too much to sides of bowl and spoon/mixer attachment.
Sprinkle surface of counter with flour and flour hands. Turn out dough onto floured surface, and knead only slightly (fold dough only 3-4 times), enough to form a ball of dough.
Place in a greased bowl, cover and place in a warm (but not hot) area. Allow to rise until double in size, about 1 hour. If risen dough is pressed down, the indentation should hold its shape.
Split dough in to 2 even portions. On a floured surface, roll each portion of dough out to a large rectangle about 1/2 inch thick.
Using a 2 1/2" round cutter, cut circles of dough from rectangle. Re-roll scraps and cut remaining circles. Repeat with 2nd portion of dough.
Place cut-out dough onto a baking sheet lined with parchment paper or a silicone baking mat. Cover and allow to rise to double in size, about 1 hour. Prepare filling in the meantime.