In a large mixing bowl, whisk together all-purpose flour and salt until well combined. In a separate bowl, mix warmed milk, melted butter, sugar, egg, and sourdough starter until smooth. Gradually incorporate this mixture into the flour, stirring until a shaggy dough forms. Once combined, allow the dough to rest for 10 minutes to hydrate.

Transfer the shaggy dough to a floured surface or a stand mixer fitted with a dough hook. Knead on medium-low speed for 8-10 minutes until it becomes smooth and elastic. The dough should be slightly tacky but not overly sticky; if needed, add small amounts of flour. Cover the bowl with plastic wrap and let the dough rise at room temperature for 1 hour.

After the initial rise, gently punch down the dough to release excess air. Cover the bowl again and place it in the refrigerator overnight.

While the dough is chilling overnight, prepare the cream cheese filling. In a mixing bowl, beat softened cream cheese, sugar, flour, vanilla extract, and a squeeze of lemon juice until smooth and creamy.

When ready to shape the kolaches, make the streusel topping by combining chilled flour, sugar, and cold butter in a bowl. Using your fingers or a pastry cutter, mix until the mixture resembles coarse crumbs.

After the dough has chilled overnight, let it sit at room temperature for about 15 minutes. Punch down the dough and transfer it to a floured surface. Shape it into a log and cut it into equal pieces, about the size of a golf ball.

Cover the shaped rolls with a clean kitchen towel and let them rise in a warm place for about 2-3 hours. Preheat your oven to 350°F (175°C) during the last 30 minutes of rising.

Once the rolls have risen, gently press your thumb or the back of a spoon in the center of each roll to create a well. Fill each indentation generously with the chilled cream cheese mixture.

Carefully place the baking sheet in the preheated oven and bake for 20-25 minutes or until the kolaches are golden brown.

Once baked, remove the Healthy Sourdough Discard Kolaches from the oven and transfer them to a wire rack to cool.