Add milk, yeast, flour, sugar, butter, eggs, egg yolk, and salt to mixing bowl or bread machine.
Knead dough for 6-8 minutes until a soft sticky dough forms. The dough is a little more sticky then most breads. If you keep kneading it will form in a dough ball.
Cover and let rise for about an hour or until doubled in size.
Preheat oven to 375 F. Line baking sheet with parchment paper or non-stick baking mat.
Divide dough into 24 pieces. Roll each piece into a ball, place on baking sheet. Flatten with the palm of your hand to about 3.5-4" in diameter. Use your fingers to punch down an indent into the center to hold the filling.
Mix sugar, flour, and melted butter together.
Brush pastries with egg wash, sprinkle about 1 tablespoon of topping on each pastry. (You can add cream cheese mixed with powdered sugar to the center or pie filling, etc. if you wish).
Bake for 13-16 minutes or until the edges are starting to brown.
Recipe by THE SEMISWEET SISTERS at http://www.thesemisweetsisters.com/2021/02/24/kolaches-czech-pastries/