For The Dough For The Filling For The Streusel

For The Dough

1. In a mixer bowl, dissolve 1 tsp sugar and yeast in warm milk. Let stand for 5 minutes.
2. Stir in additional 6 tbsp sugar, vanilla extract, salt, and egg yolk.
3. With a hook attachment and your mixer on low, slowly add 1 1⁄3 c. of all-purpose flour and all of the bread flour. Increase speed to medium and add butter. Continue to knead dough with the mixer until well-incorporated, about 2 minutes.
4. Scrape dough out onto a floured surface and knead until smooth and elastic, adding remaining all-purpose flour 1⁄3 c. at a time, as needed, to keep hands from sticking. Dough will be very soft.
5. Shape dough into a ball and place in a large bowl coated with cooking spray, turning to coat. Cover and let rise in a warm place, free from drafts, until it has doubled in size, about 1 1⁄2 hrs.
6. Punch dough down, cover again, and let rest an additional 5 minutes.
7. Use a 9x5 silicone bread loaf pan or line the bottom of a regular 9x5 pan with parchment paper & coat the sides with cooking spray.

For The Filling

1. Combine sugar, cocoa, cinnamon, nutmeg, and salt in a small bowl. Carefully stir until all ingredients are evenly distributed. Fold in chocolate chips.
2. Turn dough out on a floured surface and roll into a 16-inch square. Leaving a 1-inch border around the edges, sprinkle the filling evenly on the dough. Don't worry about the chocolate chips being equally distributed—it is almost better if they aren't.
3. Starting at one end, carefully but tightly roll the dough into a log, pinching the seams and sealing the end with your fingers.
4. Carefully twist the dough about 4 times, as if wringing a towel, and fit it into the prepared pan. Cover and let rise until doubled again, about 45 minutes.
5. Preheat the oven to 350°F.

For The Streusel

1. In a small bowl, combine powdered sugar and flour. Using a fork, cut in the butter until the mixture is crumbly.
2. Sprinkle evenly over dough.

For Baking

1. Bake at 350°F for 40 minutes, or until the loaf is lightly browned and sounds hollow when tapped.
2. Allow to cool on a wire rack, in the pan, for 10 minutes.
3. Carefully remove bread from the pan and place it back on the wire rack to cool completely.
4. Slice and enjoy.