Prepare the Dough

1. Grease two 9X5 bread pans. Set aside.
2. In a microwave or a double boiler, heat 1 cup milk to between 105°F and 110°F. Pour the milk into the bowl of a stand mixer. Sprinkle yeast on top. Add sugar and give the mixture a small stir. Place the bowl in a warm place for about 10-15 minutes. Be patient! If yeast is activated, you will see foam on top of the mixture, and even a few small bubbles. Also, if you take sniff, it will smell very much like yeast.
3. Fit stand mixer with the dough hook attachment. Add the sugar and butter and mix on a low speed until just combined (butter will not be much combined at all - this is fine).
4. Add whole egg, egg yolk, and salt on the same low speed until just combined.
5. Slowly add in flour. Once it's all in the bowl, turn the speed up to medium until it forms a soft dough. Turn the speed up to medium high and mix for 5-6 minutes (this is kneading your dough).
6. Turn the dough out onto a lightly floured surface. Grease a large bowl with a little butter (you can use the same bowl you made the dough in). Form the dough into a ball and place in the greased bowl. Cover with saran wrap or a towel and let rise in a warm place or in a bread proofer, until it has doubled in size, about 90 minutes.
7. Towards the end of the rising period,  combine all filling ingredients except for the mini chocolate chips in a medium bowl. Melt together in 15 second intervals in the microwave or over a double boiler, stirring until smooth. Keep warm.
8. Once risen, punch the dough down to get rid of air bubbles. Turn out onto a lightly floured surface and cut the dough in half.
9. Working with one dough half at a time, roll each one into a 9X13 rectangle (as close as you can, doesn't need to be exact).
10.  Spread filling evenly on both dough rectangles, making sure to leave a 1/2 inch border around the edge. Sprinkle equally with mini chocolate chips.

Braid the Loaves (Step by Step Photos in Notes Section)

1. One at a time, gently and tightly roll up one dough rectangle spread with filing into a roll and place it seam down.
2. Slice the roll in half lengthwise.
3. Criss-cross one of the halves on top of the other one, cut side down to form a somewhat bottom heavy X.
4. Twist like a rope until completely braided.
5. "Smush" ends together (yes that’s a technical term).
6. Repeat with second dough rectangle. Place braided loaves in prepared bread pans. Cover with a towel and let rest in a warm place for 20 minutes.

Assemble and Bake

1. Preheat oven to 350°F.
2. Combine all ingredients for the crumble topping in a small bowl and stir until thoroughly mixed.
3. In another small bowl, make the egg wash by whisking together egg white and the two tablespoons of milk (for a darker crust you can substitute an egg yolk for the egg white).
4. Once the loaves are done resting, brush them with the egg wash.
5. Sprinkle evenly with crumble topping. Bake in the oven for 45-50 minutes until a toothpick inserted in the center of a loaf comes out clean. Remove from heat and let cool for 5-10 minutes. Slice as desired and serve.