Grease and flour two large loaf pans. (8 or 9") Preheat oven to 325 degrees.

For filling, beat cream cheese in a small bowl till smooth. Beat in sugar, zest, and flour till smooth. Add egg and beat till thoroughly mixed. Set aside.

For bread, whisk together flour, salt, soda, and cocoa in a small mixing bowl. Stir in the chocolate chips and set aside.

In a large mixing bowl, beat oil, sugars, eggs, and vanilla till creamy. Stir in sour cream, zucchini, and orange zest. Add dry ingredients and chips and stir just till moistened.

Spread 1/4 of the batter in the bottom of each pan. Then add half of the filling to each pan. Divide the remaining batter between the two pans.

Bake for 60-80 minutes. (Depends on the size of your loaf pans.) When the bread is done, a toothpick inserted into the chocolate part should come out clean.

Cool in pans for about 10 minutes before removing to cooling racks.