Classic Cinnamon Swirl Babka

• 1 cup warm (100u0b0F to 110u0b0F) whole milk or water
• 1 (1/4-oz.) envelope active dry yeast
• 4 3/4 cups (about 20 1/4 oz.) all-purpose flour, divided
• 1/2 cup (4 oz.), plus 2 Tbsp. salted butter, softened
• 3 tablespoons granulated sugar
• 3 large eggs
• 1 large egg yolk (egg white reserved for Filling)
• 2 teaspoons vanilla extract
• 3/4 teaspoon kosher salt
• Vegetable shortening
• 2 cups packed light brown sugar
• 1/2 cup (about 2 1/8 oz.) all-purpose flour
• 1/2 cup (4 oz.) unsalted butter, softened
• 1 large egg white
• 1 1/2 tablespoons ground cinnamon
• 1/2 teaspoon kosher salt
• 1 large egg
• 1 tablespoon water

1. Prepare the Dough: Whisk together milk, yeast, and 1 cup of the flour in a medium bowl until well combined. Cover with a damp clean towel, and let stand until puffed and airy, about 20 minutes.
2. Beat butter and granulated sugar with a heavy-duty electric stand mixer fitted with the paddle attachment on medium until very pale and fluffy, about 4 minutes. Add eggs, 1 at a time, beating until well combined after each addition. Add egg yolk, vanilla, and salt, beating until combined, about 1 minute. Add milk mixture and remaining 3 3/4 cups flour, and beat on low speed until wide strands of dough pull away from bowl and color is even throughout, about 2 minutes. Cover tightly with plastic wrap, and chill 8 hours or overnight.
3. Grease 2 (9- x 5-inch) loaf pans with shortening; set aside.
4. Prepare the Filling: Stir together all Filling ingredients in a medium bowl. Divide mixture in half; set aside.
5. Assemble the Babka: Divide Dough in half. Place half in refrigerator until ready to use. Place remaining half on a well floured surface, and roll into a 20- x 12-inch rectangle (about 1/8 inch thick). Spread three-fourths of half of the Filling over Dough, leaving a 1/2-inch border. Starting with 1 long side, tightly roll up Dough, jelly-roll style. Cut log in half crosswise. Spread remaining one-fourth of half of the Filling over 1 log half. Place second log half on top to form an "X" shape, and twist logs together. Place in 1 prepared loaf pan. Cover with plastic wrap, and repeat with remaining Dough half and remaining half Filling. Place loaves in a warm (80u0b0F to 85u0b0F) place, and let stand until doubled in size, 45 minutes to 1 hour.
6. Preheat oven to 325u0b0F. Whisk together egg and water in a small bowl. Uncover loaves, and brush evenly with egg mixture. Bake in preheated oven until top is deep brown and a thermometer inserted into center of babka registers between 190u0b0F and 200u0b0F, 35 to 40 minutes. Cool completely in pans on a wire rack before slicing, about 1 hour.

warm, active dry yeast, flour, butter, granulated sugar, eggs, egg yolk, vanilla, kosher salt, vegetable shortening, brown sugar, flour, unsalted butter, egg white, ground cinnamon, kosher salt, egg, water

Taken from www.myrecipes.com/recipe/classic-cinnamon-swirl-babka (may not work)