In a small bowl or glass measuring cup, combine by stirring yeast with 1/2 cup lukewarm milk—ideally between 105ºF and 115ºF—and sugar.
Sprinkle a pinch of flour and mix gently with a fork. Let it sit for 5-10 minutes until
bubbly.
With a hand mixer or a stand mixer, whisk together flour, egg yolks, yogurt or sour
cream, vanilla, and salt in a large mixing bowl.
Incorporate 4 cups flour and continue whisking. At this point, the dough should be
flakey/crumbly.
Pour in the prepared yeast mixture and remaining 1/2 cup milk.
Just continue mixing until well combined.
a. Note: We should achieve a smooth, but sticky dough. If necessary, add more
flour (only up to max 1 cup).
With a rubber spatula, scrape down sides of the bowl to clean.
Cover with oiled plastic wrap and let it rise for more or less 45 minutes until doubled.
On a lightly floured surface, shape the dough according to your chosen recipe – twisted, braided, ringed, etc. (It works well in any cinnamon roll or coffee cake recipe)
After it is shaped, bake at 350°F, letting it rise again until nearly doubled.