Blueberry Mascarpone Babka
 
Makes 1 (9x5-inch) loaf
Ingredients
  • ½ cup (120 grams) warm whole milk (105°F/41°C to 110°F/43°C)
  • 1¼ teaspoons (4 grams) active dry yeast
  • 2½ cups (313 grams) all-purpose flour
  • 3½ tablespoons (42 grams) granulated sugar
  • 2 teaspoons (2 grams) lemon zest
  • 1½ teaspoons (4.5 grams) kosher salt
  • 2 large eggs (100 grams)
  • 1 large egg yolk (19 grams)
  • 1 teaspoon (4 grams) vanilla extract
  • ½ cup plus 2 tablespoons (141 grams) unsalted butter, softened and cubed
  • 1 large egg white (30 grams)
  • 1 tablespoon (15 grams) water
  • Mascarpone Filling (recipe follows)
  • 1 cup (46 grams) freeze-dried blueberries
  • Lemon Curd Glaze (recipe follows)
Instructions
  1. In a small bowl, gradually whisk together warm milk and yeast. Let stand until mixture is dissolved, about 5 minutes.
  2. In the bowl of a stand mixer fitted with the paddle attachment, combine flour, sugar, zest, and salt. Stir in eggs, egg yolk, and vanilla. With mixer on low speed, gradually add yeast mixture, beating until dough comes together. Increase mixer speed to medium-high, and beat for 5 to 7 minutes. Test dough using the windowpane test (see page 85). If dough is not ready, beat 1 minute more, and test again.
  3. Switch to the dough hook attachment. With mixer on medium-high speed, add butter in three additions, letting each addition incorporate before adding the next. Beat until a smooth and elastic dough forms and pulls away from sides of bowl, 4 to 6 minutes more. Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Cover surface of dough with plastic wrap, and refrigerate overnight.
  4. Spray a 9x5-inch loaf pan with cooking spray.
  5. In a small bowl, whisk together egg white and 1 tablespoon (15 grams) water. On a heavily floured surface, roll dough into a 16x12-inch rectangle. Brush edges of dough with egg wash. Spread Mascarpone Filling onto dough, leaving a ½-inch border.
  6. In the container of a blender, blend freeze-dried blueberries to a fine powder. Sprinkle ¼ cup (32 grams) blueberry powder over Mascarpone Filling.
  7. Starting with one long side, roll up dough, jelly roll style, and pinch seam to seal. (If dough is getting too warm and difficult to work with, refrigerate for 15 to 20 minutes before proceeding.) Using a bench scraper, trim 1 inch off ends, and place in center of prepared pan. Cut roll in half lengthwise. Carefully twist dough halves tightly around each other, pinching and tucking ends to seal. Place loaf over trimmed ends in prepared pan, cut sides up. (Gently compress ends of loaf to make it fit in pan.) Brush dough with egg wash. Cover and let rest in a warm,draft-free place (75°F/24°C) for 30 minutes.
  8. Preheat oven to 350°F (180°C).
  9. Bake for 15 minutes. Cover with foil, and bake, rotating pan every 15 minutes, until an instant-read thermometer inserted in center registers 205°F (96°C), 55 to 65 minutes more. Let cool in pan for 15 minutes. Remove from pan, and let cool completely on a wire rack. Drizzle with Lemon Curd Glaze.
Recipe by Bake from Scratch at https://staging.bakefromscratch.com/blueberry-mascarpone-babka/