2 (8 3/4 x 4 1/2 by 2 3/4-inch) loaf pans—glass or metal
Parchment paper
Ingredients
For the Dough
¾cupwarm milk (105° - 115°F)whole or reduced fat milk is fine
½ cupplus 2 teaspoons sugar
3tspactive dry yeast (2 ¼-oz packages)
3¼Cupsflour (all purpose) plus more for dusting
2whole large eggs
1large egg yolk
1tsppure vanilla exract
¾tspsalt
1 ¼sticks(10 tablespoons) unsalted buttercut into pieces and softened
For Egg Wash
1large egg
1tbspheavy cream
For chocolate filling
5tbspunsalted butterwell softened
2bars(3 ½ to 4-oz) fine-quality bittersweet chocolateno more than 60% cacao, finely chopped
¼cupsugar
28 ¾ by 4 ½ by 2 ¾-inch loaf pans
4piecesparchment paper
Instructions
Make dough
Stir together warm milk and 2 teaspoons sugar in bowl of mixer. Sprinkle yeast over mixture and let stand until foamy, about 5 minutes. (If the yeast doesn’t foam, discard and start over with new yeast.)
Add 1/2 cup flour to yeast mixture and beat at medium speed until combined. Add whole eggs, yolk, vanilla, salt, and remaining 1/2 cup sugar and beat until combined. Reduce speed to low, then mix in remaining 2 3/4 cups flour, about 1/2 cup at a time. Increase speed to medium, then beat in butter, a few pieces at a time, and continue to beat until dough is shiny and forms strands from paddle to bowl, about 4 minutes. (Dough will be very soft and sticky.)
Scrape dough into a lightly oiled bowl and cover bowl with plastic wrap. Let dough rise in a draft-free place at warm room temperature until doubled in bulk, 1 1/2 to 2 hours.
Assemble Babka with the filling
Line each loaf pan with 2 pieces of parchment paper (1 lengthwise and 1 crosswise)
Punch down dough with a lightly oiled rubber spatula, then halve dough. Roll out 1 piece of dough on a well floured surface with a lightly floured rolling pin into an 18 by 10-inch rectangle and arrange with a long side nearest you.
Beat together yolk and cream. Spread 2 1/2 tablespoons softened butter on dough, leaving a 1/2-inch border all around. Brush some of egg wash on long boarder nearest you.
Sprinkle half of the chocolate evenly over buttered dough, then sprinkle with half of sugar (2 tablespoons). Starting with long side farthest from you, roll dough into a snug log, pinching firmly along egg-washed seam to seal. Bring ends of log together to form a ring, pinching to seal. Twist entire ring twice to form a double figure 8 and fit into one of the lined loaf pans.
Make another babka with remaining dough, some of egg wash, and remaining butter and chocolate in same manner. Chill remaining egg wash, covered, to use later. Loosely cover pans with buttered plastic wrap (buttered side down) and let Babka rise in a draft-free place at warm room temperature until dough reaches top of pans, 1 to 2 hours. (Alternatively, let dough rise in pans in refrigerator 8 to 12 hours; bring to room temperature, 3 to 4 hours, before baking.)
Put oven rack in middle position and preheat oven to 350°F.
Brush tops of dough with remaining egg wash. Bake until tops are deep golden brown and bottoms sound hollow when tapped (when loaves are removed from pans), about 40 minutes.
Transfer loaves to a rack and cool to room temperature.
Slice, serve and enjoy!
Notes
Babkas keep, wrapped in plastic wrap and then foil, frozen 3 weeks.