Ingredients:

  • Active Sourdough Starter (100% hydration): 1 cup (225g)
  • Whole Milk (warm, about 105°F/40°C): ½ cup (120ml)
  • Granulated Sugar: ¼ cup (50g)
  • Large Egg: 1, room temperature
  • Unsalted Butter (softened): 4 tablespoons (56g)
  • All-Purpose Flour (or Bread Flour): 2 ½ cups (300g), plus extra for dusting
  • Baking Powder: 1 teaspoon
  • Salt (Fine Sea Salt): ½ teaspoon
  • Neutral Oil (Canola, Vegetable, or Peanut): 4–6 cups (for frying)
  • Powdered (Icing) Sugar (Sifted): 2 cups (240g)
  • Whole Milk or Heavy Cream: 3–4 tablespoons (for glaze)
  • Pure Vanilla Extract: 1 teaspoon (for glaze)
  • Pinch of Salt (for glaze)

Instructions:

  1. Activate the Dough: Whisk together the active sourdough starter, warm milk, sugar, and egg in a stand mixer bowl. Let rest for 5 minutes until slightly foamy.
  2. Mix the Dry Ingredients: In a separate bowl, whisk together the flour, baking powder, and salt.
  3. Form the Dough: Gradually add the dry mixture to the wet ingredients on low speed. Once combined, add the softened butter. Increase speed to medium-low and knead for 5–7 minutes until the dough is smooth, slightly tacky, but passes the windowpane test.
  4. First Proof (Bulk Fermentation): Place the dough in a lightly oiled bowl, cover, and let rise in a warm spot until nearly doubled (this could take 1 to 2 hours depending on your starter's strength).
  5. Roll and Cut: Turn the dough onto a lightly floured surface. Gently roll to a uniform ½-inch thickness. Use cutters to punch out donuts and holes. Place cutouts onto parchment-lined baking sheets.
  6. Second Proof (Final Proof): Cover the cut donuts loosely and let them rest for 30–45 minutes. They should look slightly puffy.
  7. Heat the Oil: Heat the neutral oil in your pot until it reaches a steady 365°F (185°C). Use a thermometer!
  8. Fry the Donuts: Carefully lower 2–3 donuts into the oil. Fry for 60–90 seconds per side until beautifully golden brown.
  9. Drain: Remove donuts with a spider strainer and place immediately onto wire cooling racks set over a baking sheet.
  10. Make the Glaze: While donuts cool slightly, whisk all glaze ingredients (powdered sugar, milk/cream, vanilla, salt) together until perfectly smooth. Adjust liquid for desired thickness.
  11. Glaze and Serve: Dip the still-warm donuts into the glaze, allowing excess to drip off. Place back on the rack to set. Serve immediately.