Authentic Czech Kolache (Koláče) With Fruit Filling Recipe - Very Good Cook

Ingredients

• For the dough:
• 2 whole eggs (1 egg for the dough; 1 egg for brushing the dough)
• 2 egg yolks
• 1 cup lukewarm whole milk
• 3½ cups unbleached all-purpose flour
• Pinch of salt
• ¼ cup powdered sugar
• 1 tablespoon active dry yeast
• 10 tablespoons (140g) softened unsalted butter
• 1 tablespoon vegetable oil, for greasing the bowl
• For the streusel topping:
• 1 cup unbleached all-purpose flour
• 1/3 cup sugar
• 7 tablespoons (100g) cold unsalted butter, cut into 1/2-inch cubes
• For the fruit topping:
• 20 fresh ripe, soft apricots, pitted, cut in half, or quarters if too big
• 4 cups fresh strawberries, destemmed, cut in half, or quarters if too big
• 4 cups fresh blueberries