Combine 1 & 1/2 cups (180g) flour, yeast, sugar, and salt in a large mixing bowl or the bowl of a stand mixer.

Gradually add the butter mixture to the flour mixture. Beat at medium speed for 2 minutes. Scrape down the sides of the bowl.

Add the eggs and 1 cup (120g) flour. Beat at high speed for 2 minutes.

Stir in the remaining 2 cups (240g) flour. The dough will be stiff.

Cover and refrigerate 2 to 24 hours.

Line baking sheets with parchment paper or silicone liners.

Divide the dough into 24 equal portions. (Use your kitchen scale to make this simpler and more accurate.) Shape each portion into a ball.

Place the balls of dough on the prepared pans, leaving about 2 inches between them.

Cover and let rest for 15 minutes.

Make a deep, wide indentation in each ball of dough. Leave about a 1/2-inch border around the outside. Fill each indentation with a heaping teaspoon of pastry filling.

Spray plastic wrap with cooking spray, and use to cover the kolaches. Let the kolaches rise in a warm, draft-free place until doubled in size (about 1 hour).

Bake the kolaches 18 to 23 minutes, or until lightly browned.

Cool on the pans on a wire rack for 5 minutes. Then transfer from the pan to a wire rack to cool completely.

If desired, sprinkle the top of each kolache with confectioners' sugar.