Chocolate Babka

Name: Chocolate Babka
Cook time: 27 h 30 min
Total time: 27 h 30 min
Cuisine: European, Eastern European
Ingredients: 1/2 cup/118 milliliters whole milk; 1 package (1/4 ounce/7 grams) active dry yeast; 1/3 cup/67 grams granulated sugar, plus a pinch; 4 1/4 cups/531 grams all-purpose flour, more as needed; 1 1/2 teaspoons fine sea salt; 1 teaspoon vanilla extract; 1 teaspoon grated lemon zest (optional); 1/2 teaspoon freshly grated nutmeg; 4 large eggs, at room temperature, lightly beaten; 10 tablespoons/140 grams unsalted butter, at room temperature, plus more for greasing bowls and pans; 1/2 cup/100 grams granulated sugar; 3/4 cup/177 milliliters heavy cream or half-and-half; Pinch kosher salt; 6 ounces/170 grams extra bittersweet chocolate, preferably between 66 and 74 percent cocoa, coarsely chopped; 8 tablespoons/112 grams/1 stick unsalted butter, diced, at room temperature; 2 teaspoons/10 milliliters vanilla extract; 1/2 cup/60 grams all-purpose flour; 3 tablespoons/45 grams granulated sugar; 1 1/2 tablespoons/11 grams cocoa powder; 1/2 teaspoon kosher salt; 4 1/2 tablespoons/64 grams unsalted butter, melted; 1/3 cup/60 grams mini semisweet chocolate chips; 2/3 cup/135 grams granulated sugar