Combine 2 cups of all-purpose flour and 1 teaspoon of salt in a stand mixer bowl.

Whisk together 1 cup of warm milk, ¼ cup of melted butter, 2 tablespoons of sugar, 1 egg, and 1 egg yolk in a separate bowl.

Pour the wet mixture into the dry ingredients, and mix on low speed.

Knead the dough for 8–10 minutes until smooth and elastic.

Let the dough rise at room temperature for 1 hour.

Mix together 8 ounces of softened cream cheese, ¼ cup of sugar, and 1 teaspoon of vanilla until smooth.

Combine ⅓ cup of flour, ¼ cup of sugar, and ¼ cup of cold butter to make the streusel topping.

Shape the risen dough into 12 balls and let them rise for an additional 2-3 hours.

Preheat your oven to 350°F (175°C) about 20 minutes before the final rise is complete.

Fill the indents in each dough ball with the cream cheese filling, brush with egg wash, and sprinkle with streusel before baking for 20-25 minutes.

Let the kolaches cool on a wire rack for about 10 minutes before serving.