In a large bowl, whisk together 2 cups of the flour, sugar, yeast, and salt. Warm the milk to 110°F and combine it with the melted and cooled butter, then pour this mixture into the dry ingredients. Beat vigorously for 3 minutes to develop the gluten structure. Gradually mix in the remaining 6.25 cups of flour until a shaggy dough forms. Knead the dough for 6-8 minutes until it becomes smooth and elastic, then place it in a lightly oiled bowl, cover with plastic wrap, and let it rise at room temperature for about 1 hour until doubled in size.

Punch down the dough from Step 1 to release excess gas. Divide the dough into 24 equal pieces and shape each into a 1-1/2 inch ball, then gently flatten each ball into a disc about 1/4 inch thick. Arrange the discs on parchment-lined baking sheets, leaving about 2 inches between each one. Cover loosely with plastic wrap and let rise for 30 minutes at room temperature until puffy.

While the shaped dough is rising, preheat your oven to 350°F. In a small bowl, whisk together the egg yolks and vanilla extract until well combined. This egg wash will give the kolaches a beautiful golden shine.

Using your thumb or a small spoon handle, press a shallow well into the center of each flattened dough disc from Step 2—don't press all the way through. Spoon about 1 tablespoon of apricot filling into each indentation. Brush the egg wash mixture from Step 3 around the edges of each kolach (avoiding filling so it doesn't get sealed), then lightly brush each one with melted butter for extra richness.

Bake the kolaches in the preheated 350°F oven for 15-20 minutes until they are golden brown and the dough springs back when lightly touched. I like to rotate the baking sheets halfway through to ensure even browning. Remove from the oven and let cool on the pan for 5 minutes before transferring to a wire rack.

While the kolaches cool, prepare the glaze by whisking together the sifted powdered sugar, water, and fresh lemon juice until smooth and pourable. Once the kolaches have cooled to room temperature, drizzle the glaze generously over the top of each one in a thin stream. I find that a light hand with the lemon juice really brightens the glaze without overpowering it—start with less and add more if you want tangier flavor. Let the glaze set for 10 minutes before serving.