Express Sourdough Butter Croissants

1. In the bowl of a stand mixer, combine the sourdough starter, flour, milk, softened butter, sugar, and salt. Mix on medium speed for 8 minutes until the dough forms a smooth ball. Cover the bowl with plastic wrap and let ferment at room temperature for 5–7 hours, or until the dough has nearly doubled in size and feels light and airy. For faster fermentation, place the bowl in the oven with the light on.

2. Roll the dough into a large rectangle, about 12 × 18 inches. In a bowl, mix the cold grated butter with the flour. The dough will be folded into thirds. Sprinkle half of the butter mixture over the center section. Fold the right third over the center, sprinkle the remaining butter, then fold the left third on top, like folding a brochure.

3. Roll the dough again into a large rectangle, then fold into thirds once more. Cover with plastic wrap and let rest 20–30 minutes at room temperature.

4. Roll out the dough into a rectangle about 1 cm thick. Trim the edges for a straight rectangle. Cut the dough into 4 long rectangles, then cut each rectangle into triangles, giving you 8 triangles total. Make a 2 cm slit in the middle of the base of each triangle (the shortest side).

5. Roll each triangle into a croissant, keeping the base tight and edges neatly rolled. Gently press the dough to create maximum layering for each croissant.

6. Place the formed croissants on a parchment-lined baking sheet and cover with plastic wrap to prevent drying. Let them ferment at room temperature for 3–4 hours, until doubled in size and puffy. Ensure the room temperature is below 24 °C. Avoid placing them in the oven at this stage, as heat could melt the butter and ruin the layers.

7. Preheat the oven to 375 °F. Brush the croissants with cream, then bake for 15–20 minutes, until golden and crisp.

8. Cool on a wire rack before enjoying.