The dough for these strudels is very similar to brioche soft, sweet, and buttery and the vibrant blue filling has a wonderfully deep and complex flavor. The filling can be made up to three days in advance. It will be very stiff when cold and won’t spread easily, so be sure to bring it to room temperature and stir it well before using. Store the baked strudel in an airtight container, at room temperature, for up to three days, or freeze for up to one month.
Ingredients
For the Dough
- 4¼ cups all-purpose flour, spooned and leveled, plus more for the work surface
- 1 teaspoon plus a pinch kosher salt
- ½ cup unsalted butter, melted, plus more for the bowl
- 1 cup whole milk, warmed to 100 to 110ºF
- 2 packages active dry yeast (¼ ounce each)
- ½ cup granulated sugar
- 3 large eggs
For the Filling
- 3 tablespoons unsalted butter
- 2 cups fresh blueberries
- ⅓ cup packed light-brown sugar
- 1 cup poppy seeds, finely ground in a spice grinder
For Assembly
- 1 large egg yolk
- 2 tablespoons turbinado sugar
How to Make It
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Make the Dough
- Whisk together the flour and salt in a bowl. Rub the inside of a separate bowl with butter.
- Pour the milk into a bowl and sprinkle the yeast. Let sit until the yeast is bubbling, 5 to 7 minutes (if the yeast does not bubble discard the mixture and start again). Whisk in the sugar, eggs, and butter.
- Stir the dry ingredients into the wet ingredients, 1 cup at a time, until combined. Turn the dough out onto a floured work surface. Knead until the dough is uniform, about 5 minutes.
- Transfer the dough to the buttered bowl and turn to coat with the butter. Cover the bowl with a dishtowel and place it in a warm (but not hot) place. Let the dough rise until doubled in size, 1 to 1½ hours. Make the Filling
- Melt the butter in a medium saucepan over medium heat. Add the blueberries and sugar. Mash with a potato masher and cook, stirring occasionally, until thickened, 10 to 12 minutes. Stir in the poppy seeds. Cool to room temperature. Assemble the Strudels
- Preheat oven to 350°F. Line 2 rimmed baking sheets with parchment paper.
- Divide the dough into two equal-sized pieces. Working one piece at a time, roll the dough into a 11 x 14-inch rectangle, on a floured work surface. Spread half of the blueberry mixture on the dough, leaving a 1-inch border on all sides. Roll up the dough lengthwise, keeping it as tight as possible. Transfer to one of the lined baking sheets, seamside down. Repeat with the remaining dough and blueberry mixture.
- Cover the rolls with dishtowels and place them in a warm (but not hot) place. Let the dough rise until slightly puffed, 30 minutes to 1 hour.
- Combine the egg yolk and 1 teaspoon water in a bowl. Brush the tops and sides of the rolls with the egg wash (you will have some leftover). Poke the top of each roll five times with the tines of the fork, being sure to go at least three quarters of the way through. (Poking holes in the dough allows steam to escape and helps prevent the dough from cracking. Don’t be tempted to poke more holes. Too many weakens the dough and causes large cracks.) Sprinkle with the turbinado sugar, dividing evenly.
- Bake, rotating the sheets front to back and top to bottom halfway through, until golden-brown, 25 to 35 minutes. Eat warm or at room temperature.