Sourdough Starter Preparation: Mix 1 tablespoon of your starter with 60g water and 60g flour in a small bowl or pint size mason jar. Cover and leave at room temperature for 6 to 12 hours until it’s bubbly and doubled in size.

Scalding Milk: To ensure the best texture and fermentation activity, scald the milk. Pour a bit extra milk into a saucepan (to account for evaporation) and heat over medium until it starts to steam.Once it reaches 130-140°F, set aside 100g of the warm milk to cool slightly before adding to the dough.

Making the Dough: Combine the scalded milk, water, sugar, and sourdough starter in a large mixing bowl. Add the flour, vanilla, and egg, and mix until a shaggy dough forms. If using a stand mixer, knead on low speed with a dough hook for 6-8 minutes; if kneading by hand, expect 8-10 minutes. Add softened butter, 1 tablespoon at a time, and knead until the dough is smooth and no longer sticky.

Bulk Fermentation: Transfer the dough to an airtight container or cover with plastic wrap in a large bowl. Let it ferment for 4-8 hours in a warm place, or until it has doubled in size.

Shaping the Crescent Rolls: Prepare two baking sheets by placing a sheet of parchment on each sheet pan. Place the dough on a lightly floured surface and divide into two equal halves. Roll each half into a 10-12 inch large circle and cut each circle with a rolling pizza cutter or a sharp knife into 12 triangular wedges. Starting from the wide end, roll each triangle toward the point, forming a classic crescent shape. Place the rolls on a parchment-lined baking sheet, leaving 2-3 inches of space between each. If desired, you can keep the rolls straight or curve the ends to make it look like the classic croissant shape.

Proofing the Crescent Rolls: Cover with plastic wrap and proof at room temperature for 1-2 hours until the rolls are puffy and soft. They should be at least 1.5 times larger than their original size.

Baking: Preheat the oven to 375°F. Prepare egg wash by whisking the egg with a 1/4-1/2 teaspoon of water. For golden-brown crescents, brush the tops with egg wash. If desired, you can add a sprinkle of coarse salt over the egg wash.Place into the preheated oven and bake for 16-20 minutes, until golden brown and fluffy.