1. Step 1: Prepare the Dough (Day 1)

• Activate the Sourdough Starter:
• If your sourdough starter has been stored in the fridge, bring it to life by feeding it about 4–6 hours before making your donuts. It should be bubbly and active before you begin.

2. Mixing the Dough:

• Combine the sourdough starter, warm milk, eggs, sugar, softened butter, and vanilla extract in a large bowl. Mix until smooth.
• Gradually add the bread flour and salt. Stir until the dough forms a shaggy mass.

3. Knead the Dough:

• Turn the dough out onto a lightly floured surface or use a stand mixer with a dough hook. Knead for about 8–10 minutes (or mix for 5–7 minutes) until the dough becomes smooth and elastic.
• The dough should be soft but not sticky. If it’s too sticky, add small amounts of flour, one tablespoon at a time.

4. Bulk Fermentation:

• Place the dough in a lightly greased bowl, cover with a damp cloth, and allow it to rise at room temperature for about 4–6 hours. It should nearly double in size.

5. Cold-Proof Overnight:

• Transfer the bowl to the refrigerator and allow the dough to rest overnight. This slow fermentation enhances the flavor and makes the dough easier to work with.

Step 2: Shape and Proof the Donuts (Day 2)

1. Roll the Dough:

• Remove the dough from the fridge and place it on a floured surface. Roll it out to about ½ inch thickness.

2. Cut the Donuts:

• Use a donut cutter or two round cutters to shape your donuts. Don’t forget to save the donut holes! Re-roll scraps to make additional donuts.

3. Second Rise:

• Place the shaped donuts on a parchment-lined baking sheet. Cover them with a damp cloth and let them rise at room temperature for 1–2 hours. They should puff up noticeably.

Step 3A: Fry the Donuts

1. Heat the Oil:

• Fill a deep pan with at least 2 inches of oil and heat to 350°F. Use a thermometer to keep the temperature consistent.

2. Fry the Donuts:

• Gently lower the donuts into the oil, a few at a time, without overcrowding. Fry them for about 1–2 minutes per side until they’re golden brown. Use a slotted spoon to remove them and transfer to a cooling rack lined with paper towels.

3. Fry the Donut Holes:

• Don’t forget to fry the holes! They take a little less time—around 1 minute per side.

Step 3B: Bake the Donuts (For a Lighter Option)

1. Preheat the Oven:

• Set your oven to 350°F.

2. Bake the Donuts:

• Place the donuts on a parchment-lined baking sheet and bake for 13–15 minutes, or until they’re lightly golden.

3. Optional Butter Coating:

• Brush the hot baked donuts with melted butter for added richness before coating or glazing.

Step 4: Glaze or Coat the Donuts

1. Make the Glaze:

• Combine powdered sugar, 2 tablespoons of milk, and vanilla extract in a bowl. Stir until smooth. Add a little more milk if the glaze is too thick.
• Dip the cooled donuts into the glaze, letting the excess drip off. Place them on a rack to set.

2. Cinnamon Sugar Coating:

• Mix granulated sugar and cinnamon in a wide bowl.
• While the donuts are still warm, roll them in the cinnamon sugar mixture until fully coated.

3. Serve and Enjoy:

• Whether glazed or covered in cinnamon sugar, your homemade sourdough donuts are now ready to enjoy!