Dissolve yeast in lukewarm water and let it proof.
Combine flour, ½ cup sugar, and salt in a bowl.
Add melted butter, milk, and yeast mixture to the dry ingredients and knead into a paste.
Let the dough rise until doubled in size.
Flatten the dough, chill in the refrigerator, and repeat the buttering and folding process.
Roll out the dough, brush with egg-sugar mixture, roll up, cut into pieces, and place in muffin cups to rise.
Bake the rolls until brown and crisp.
Roll the baked buns in cinnamon-sugar mixture.
For the butter pack, mix cold unsalted butter with flour and refrigerate in portions.