Preheat oven 375.......Mix yeast and a pinch of sugar and 1 cup warm water in a small bowl and set aside while you measure out the dry ingredients, or until frothy.
Whisk 3 1/2 cups flour, remaining 1/2 cup sugar and salt in a very large bowl. Pour in the yeast mixture and stir with wooden spoon. Add 1 egg, vegetable oil and 1 cup warm water; stir until combined. You may have to add a little more warm water. Gradually sstir in the remaining 3 1/2 cups flour until dough comes together. Mix in chocolate chips. Turn dough out onto a floured surface and knead about 5 minutes. Transfer to a large slightly oiled bowl, cover with plastic wrap and let rise in warm place until doubled in size.....about 1 1/2 hours, check after 1 hr.
Divide dough into 3 equal portions. On floured board roll each portion into 1 1/2 to 2 inch wide strand about 16 inches long. Lay strands side by side on parchment paper and braid the strands, pinch the dough together at the end. Slide the parchment and bread onto a baking sheet. Beat the remaining egg with 1 tablspoon water in small bowl and bruch the egg wash all over the loaf. Bake until golden brown, about 30 minutes, test.