The night before you plan to make the Kolache, in a large bowl dissolve yeast in warm water. Add milk, sour cream, sugar, butter, eggs, salt and 1 ½ cups of the flour. Beat until smooth.
Beat in remaining flour to form a soft dough. Transfer to a greased bowl and refrigerate overnight.
Roll dough out into a 14 x 12 inch rectangle. Spread with filling.
Roll like a cinnamon or jelly roll to make a 14 inch long cylinder. Pinch edges to seal, place seam side down on a parchment paper lined baking sheet. Let rise until doubled in size about 1 ½ hours.
Bake at 350°F for 35-40 minutes. Let cool on a wire rack.
Create a thin glaze with the powdered sugar and milk and drizzle over the top. Slice and serve.
Notes
The almond or poppy seed filling can usually be found with the pie fillings at the grocery store.