• Activate the yeast. Combine warm water, yeast, and 1 teaspoon of sugar in a small bowl. Stir and let sit for 10 minutes, until the yeast is foamy and active. 
• Mix the dough. In a large bowl, mix together the sugar, milk, melted shortening or butter, salt, and egg yolk. Stir in the yeast mixture. Add the sifted bread flour 1 cup at a time until 3 cups are incorporated. Stir until a sticky dough starts to form.
• Knead. Sprinkle the remaining ⅓ cup bread flour onto a hard work surface. Turn the dough out and knead for 10-12 minutes, until smooth and elastic. The finished dough should be soft and slightly sticky. 
• Let rise. Transfer the dough to a lightly greased bowl and cover. Let rise for 1 hour until puffy and nearly doubled in size.
• Punch dough down. Roll into a log and cut into 12 equal size pieces, approximately the size of golf balls (~2.5 ounces each). Place dough balls in a lightly greased 9 X 13 pan and brush with 1 tbsp. of melted butter. Cover and let rise for 30 minutes.
• Make wells in the center by pressing a lightly floured ¼ cup measuring cup into the center of each dough ball. Fill each dough ball with 1 Tablespoon of cream cheese filling. Brush sides with more melted butter. Sprinkle 1-2 tsp. of posypka (streusel topping) over each kolache. Cover and let rise for 1 – 2 hours.
• Bake kolaches at 350℉ for 28-33 minutes or until golden brown. Remove from oven and allow to cool for about 1 hour before cutting into them.

Cream Cheese Filling

• In a high speed mixer, whisk together cream cheese, sugar, egg yolk and vanilla extract for 1-2 minutes or until creamy.

Streusel Topping

• In a medium bowl, combine flour, sugar, salt, cinnamon. Cut butter into dry mixture until coarse crumbles form.