Chocolate Babka

Directions

1. 1
   Stir the yeast into the milk to dissolve. Let sit until foamy.
2. 2
   While the yeast proofs cream the butter and sugar together in the bowl of a stand mixer. Add the oil and vanilla extract and mix well to combine. Then add the egg yolks one at a time, mixing until each yolk is incorporated before adding the next. Increase the mixer speed to high and beat the mixture for about 2 minutes.
3. 3
   Turn the mixer to low and add the flour and salt, followed by the milk and yeast mixture. Switch to the dough hook attachment and mix the dough until a soft, tacky dough forms. Transfer the dough to a floured surface and knead by hand for two more minutes. The dough should feel soft, supple and smooth. Move the dough to a clean, oiled bowl and cover with plastic wrap. Let the dough rise at a moderate room temperature for about 2 hours or until almost doubled in size. Alternately, you can let the dough rise overnight in the refrigerator and shape it the next day.
4. 4
   Prepare the filling while the dough is rising. Put all of the ingredient into a large bowl and use a pastry blender or bench scraper to cut the ingredients together into a streusel-like crumble.
5. 5
   To shape the bread: Roll the risen dough on a lightly floured surface into a roughly 15x18 inch rectangle. Gently lift the dough to make sure that it will easily release from the work surface. Sprinkle the filling mixture evenly over the top of the dough leaving a 1/4-inch border around the edges then roll the dough from the long end into a tight log about 20 inches long. Gently bend the dough into a U-Shape and twist the arms of the dough two or three times around each other to form the loaf, then pinch the seams together. Place the dough into a greased 9-inch by 5-inch loaf pan. Cover with plastic wrap and let rise at room until the babka fills the pan, 1-2 hours.
6. 6
   Preheat oven to 350°F.
7. 7
   Prepare the streusel: Combine all of the streusel ingredients in a bowl and mix until crumbly. When the loaf has risen completely, brush with egg wash made from 1 egg + 1T water and sprinkle the streusel mixture over the top. Use a toothpick to poke a few holes in the top of the loaf which will release any air pockets trapped between the folds of the dough and filling.
8. 8
   Put the loaf pan on a baking sheet and bake for 20-25 minutes, then rotate the pan and bake for 20-30 more minutes. The loaf will be deep golden brown on top and sound hollow when the bottom is tapped when finished. You can also use a thermometer to check the internal temperature which will be 185° when the loaf is finished. Let the babka cool to room temperature before slicing.