Combine 1-1/2 cups flour, undissolved yeast, sugar and salt in a large mixer bowl.
Heat water, sour cream and butter until very warm (120° to 130°F).
Gradually add to flour mixture. Beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally.
Add eggs and 1 cup flour; beat 2 minutes at high speed.
Stir in remaining 2 cups flour (by hand so as not to overwork) to make a stiff batter. Cover tightly with plastic wrap; refrigerate 2 to 24 hours.
Remove dough from refrigerator. Divide into 24 equal pieces; shape each into a ball. Place balls on greased, or parchment lined baking sheets 2 inches apart. Cover; let rest 15 minutes.
While the dough is resting, prepare the cream cheese filling and streusel topping.
For the Cream Cheese Filling
In a medium bowl with an electric mixer, combine the cream cheese, sugar, and egg until fully incorporated and smooth.
Sprinkle in flour and mix until combined.
For the Streusel Topping
Place the flour, sugar, and butter into a food processor and pulse until crumbly, or use a pastry blender to incorporate the butter into the flour and sugar.
To Assemble the Kolaches
Make a deep and wide indentation on each dough ball by pushing outward toward edge, leaving 1/2-inch ridge around outside. I used a metal tablespoon measuring spoon that was coated with nonstick cooking spray to create the indentations.
Fill with a heaping teaspoon of the cream cheese mixture and top that with a heaping teaspoon of of pastry filling.
Sprinkle kolaches with streusel topping.
Cover with plastic wrap that has been sprayed with cooking spray.
Let rise in warm, draft-free place until doubled in size, about 1 hour.
Bake in preheated 350°F oven for 18 to 23 minutes or until done.