Sourdough Boston Cream Donuts (100% Sourdough Recipe)
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Sourdough Boston Cream Donuts are 100% sourdough, naturally fermented, filled with a from-scratch creamy vanilla custard, and topped with a simple chocolate ganache. If you’re looking to wow your friends and family, this is the recipe to do it with!
Whenever I make homemade donuts, my family gets *so* excited when they see that I’m filling them with my homemade vanilla custard recipe–oh. my. goodness. Pure bliss.
This is such a fun recipe to make, because it is incredibly rewarding and they look so beautiful–these are absolutely bakery-style donuts, but way better because they’ll be homemade by you.
These brioche sourdough donuts are a variation of these sourdough glazed donuts. If you’re looking for something less time-consuming, you can make these sourdough discard vanilla custard-filled donuts, which don’t require active sourdough starter.
Looking for other sourdough brioche recipes? Check these out!
Why You’ll Love This Recipe
- Perfect for special occasions, weekend baking, or impressing a crowd with minimal effort
- Bakery-style sourdough donuts made at home with rich, complex flavor from long fermentation
- Soft, airy brioche dough with a light tang that perfectly balances the sweet fillings
- Silky homemade vanilla custard that pipes beautifully into the center of each donut
- Thick, glossy chocolate ganache topping for that classic Boston cream finish
Step-By-Step Instructions
Add the sourdough starter, warm milk, flour, eggs, salt, sugar, and vanilla to the bowl of a stand mixer fitted with a dough hook. Mix until a shaggy dough forms.
Add the softened butter one tablespoon at a time while mixing. Knead for about 10 minutes until smooth, elastic, and slightly sticky.
Transfer the dough to a greased bowl, cover, and let bulk ferment 6-10 hours until risen about 50–60%.
At this point, you can cover and place in the fridge overnight or continue on to the next steps.
In a medium bowl, whisk together the egg yolks and cornstarch until completely smooth. Set aside.
In a saucepan over medium heat, whisk together the milk, sugar, and salt. Heat until steaming but not boiling.
Slowly pour about 1 cup of the hot milk mixture into the egg mixture while whisking constantly to temper the eggs.
Pour the tempered egg mixture back into the saucepan and cook, whisking constantly, until thick and smooth. Stir in the vanilla extract.
Transfer the custard to a bowl and press plastic wrap directly onto the surface. Refrigerate until completely chilled.
Roll the dough to 1/2-inch thick and cut out donuts. Place each donut onto parchment paper squares on a baking sheet.
Cover loosely with plastic wrap and let rise 2–3 hours, or until the donuts look puffy and airy.
Once the dough has risen, heat the oil in a heavy-bottomed saucepan.
Any neutral oil works, such as coconut oil, canola oil, or vegetable oil. Fill the pan with about 2-3 inches of oil.
Heat oil to 340–360°F and fry the donuts for 1–2 minutes per side until golden brown.
Keep an eye on the oil, making sure it doesn’t go above 360°F. Doing so can cause the donuts to burn fast and not cook completely in the center. Transfer to a wire rack and cool completely.
In a saucepan, heat the heavy cream until steaming. Whisk in the chocolate chips and butter until smooth and glossy. Finally, add the vanilla extract.
Transfer the chilled custard to a piping bag, use a knife and slice a small hole in the side of the donuts. Pipe filling into the center of each donut.
Dip the tops of the filled donuts into the chocolate ganache. Let set for a few minutes before serving.
Helpful Tips for the Best Sourdough Boston Cream Donuts
- Enjoy the donuts the same day they’re assembled for the best texture and flavor.
- Use a strong, active sourdough starter to ensure a good rise and light, airy donut texture.
- Don’t rush fermentation—long, slow bulk fermentation is what gives the brioche dough its flavor and softness.
- Keep your dough slightly sticky; avoid adding extra flour or the donuts can turn dense.
- Maintain steady oil temperature (340–360°F) for even frying and a golden exterior without greasiness.
- Fry a test donut first to dial in your timing and temperature before cooking the full batch.
- Always chill the custard completely before piping so it stays thick and doesn’t run out of the donuts.
- Let donuts cool fully before filling to prevent the custard from melting inside.
- Use a piping bag with a long tip to evenly fill the center without splitting the donut.
- Dip ganache while it’s thick and glossy—not hot—for the best smooth topping that sets properly.
Equipment Needed
- Stand mixer fitted with a dough hook attachment
- Large mixing bowls
- Medium saucepan (for custard and ganache)
- Whisk
- Silicone spatula
- Plastic wrap or airtight cover
- Kitchen scale (recommended for accuracy)
- Rolling pin
- Round biscuit cutter or glass (for cutting donuts)
- Baking sheet
- Parchment paper squares (for proofing donuts)
- Heavy-bottomed pot or Dutch oven (for frying)
- Deep-fry or candy thermometer
- Slotted spoon or spider strainer
- Wire cooling rack
- Paper towels
- Piping bag with round tip (for custard filling)
Storage Instructions
- If making ahead, you can store unfilled fried donuts at room temperature for up to 24 hours, then fill and glaze before serving.
- Store filled sourdough Boston cream donuts in an airtight container in the refrigerator for up to 3 days.
- Because of the custard filling, these donuts should always be refrigerated rather than kept at room temperature.
- For best texture, let them sit at room temperature for 10–15 minutes before serving.
- Avoid freezing assembled donuts, as the custard and ganache can separate and become watery after thawing.
Ingredients
Brioche Sourdough Donut Dough
- 2/3 cup active sourdough starter 150 g
- 1/2 cup warm whole milk 100–110°F (122 g)
- 2 3/4 cups all-purpose flour 390 g
- 2 large eggs room temperature (105 g)
- 1/4 teaspoon salt 2 g
- 1/4 cup granulated sugar 53 g
- 1 teaspoon vanilla bean paste or vanilla extract 5 g
- 8 tablespoons salted butter softened (113 g)
Vanilla Custard Filling
- 5 egg yolks
- 1/4 cup cornstarch 30 g
- 2 cups whole milk 480 g
- 1/2 cup granulated sugar 100 g
- 1/4 teaspoon salt 1.5 g
- 1 teaspoon vanilla extract 5 g
Chocolate Ganache
- 1/4 cup heavy cream 60 g
- 1/2 cup semisweet chocolate chips 85 g
- 1/2 tablespoon unsalted butter 7 g
- 1/2 teaspoon vanilla extract 2 g
For Frying
- Coconut oil or another neutral frying oil
Instructions
Make the Vanilla Custard (Make at least 2 hours before you fill the donuts)
- Prepare the custard ahead of time so it has plenty of time to chill before filling the donuts.
- In a medium bowl, whisk together the egg yolks and cornstarch until completely smooth. Set aside.
- In a medium saucepan over medium heat, combine the milk, sugar, and salt. Whisk frequently and heat until the mixture is steaming but not boiling.
- Scoop out about 1 cup (240 g) of the hot milk mixture and slowly drizzle it into the egg mixture while whisking constantly. This tempers the eggs and prevents scrambling.
- Gradually pour the tempered egg mixture back into the saucepan with the remaining milk, whisking continuously.
- Cook over medium heat, whisking constantly, for 3–5 minutes or until the custard becomes thick and smooth.
- Remove from the heat and stir in the vanilla extract.
- Transfer the custard to a clean bowl and press plastic wrap directly onto the surface to prevent a skin from forming. Refrigerate for at least 2 hours or until completely chilled.
Prepare the Dough
- Add the sourdough starter, warm milk, flour, eggs, salt, sugar, and vanilla to the bowl of a stand mixer fitted with the dough hook attachment.
- Mix on low speed until the ingredients come together into a shaggy dough.
- With the mixer running on low, add the softened butter one tablespoon at a time, allowing each piece to fully incorporate before adding the next.
- Increase the speed to medium-high or high and knead for about 7 minutes, or until the dough is smooth, elastic, and pulling away from the sides of the bowl.
- The dough will be very soft and slightly sticky. Avoid adding extra flour, as this helps create light and fluffy donuts.
Bulk Fermentation
- Transfer the dough to a large lightly greased bowl and cover tightly with plastic wrap.
- Let the dough bulk ferment for up to 6-10 hours, depending on the temperature of your kitchen.
- The dough should rise about 50–60%. Brioche doughs naturally ferment more slowly due to the butter and eggs. Once it bulk ferments, you can continue on to shaping and giving them a second rise, or you can cover tightly and refrigerate overnight to make the next day.
Shape the Donuts
- Turn the dough out onto a lightly floured surface.
- Roll the dough to about 1/2-inch thickness. Using a round biscuit cutter or the rim of a glass, cut out 12 donuts. Depending on the size of your cutter, you may be able to get a couple extra donuts.
- Place each donut onto an individual square of parchment paper and transfer them to a baking sheet.
Final Rise
- Cover the donuts loosely and let them rise in a warm place for 2–3 hours, or until noticeably puffy.
- To test if the donuts are ready, gently press your finger into the dough. If the indentation slowly springs back, the donuts are fully proofed. If it springs back quickly, they need more time.
Fry the Donuts
- Add coconut oil or another neutral oil to a heavy-bottomed pot, filling it 2–3 inches deep.
- Heat the oil to 340–360°F. Maintaining the proper oil temperature is important to ensure the donuts cook evenly without burning.
- Carefully lower the donuts into the hot oil using the parchment squares. The parchment will naturally release after a few seconds and can be removed with tongs.
- Fry the donuts in batches for 1–2 minutes per side, or until deeply golden brown.
- Transfer the fried donuts to a wire rack lined with paper towels underneath to catch excess oil. Allow the donuts to cool completely before filling.
Make the Chocolate Ganache
- In a small saucepan over low heat, warm the heavy cream until steaming but not boiling.
- Add the chocolate chips and butter, whisking continuously until completely melted and smooth.
- Remove from the heat and stir in the vanilla extract. Let the ganache cool slightly until thick, glossy, and perfect for dipping.
Fill and Assemble
- Transfer the chilled custard to a piping bag fitted with a round tip.
- Using a small knife or skewer, poke a hole into the side of each donut. Pipe the vanilla custard into the center until the donut feels full and slightly heavy.
- Dip the tops of the filled donuts into the glossy chocolate ganache, allowing any excess to drip off.
- Let the ganache set for a few minutes before serving.
