Preheat oven to 325°F. Grease and flour two 9x5x3-inch loaf pans; set aside.

In a medium bowl, stir together the flour and salt. Set aside. In a small bowl, beat together the eggs, egg yolks, and vanilla. Set aside.

In a large bowl, cream the butter and sugar with an electric mixer on medium-high speed until light and fluffy (about 4-5 minutes). Reduce the mixer speed to medium and add the egg mixture gradually. Continue to mix for an additional 2-3 minutes, scraping down the sides of the bowl, if necessary. Switch the mixer to low speed and gradually add the flour mixture and beat just until blended. Stir in the chocolate chips.

Divide the batter between the two loaf pans, smoothing out the top. Bake for 1 hour and 10 minutes to 1 hour and 20 minutes - or until a toothpick inserted near the center tests clean. Cool in the pan on a wire rack for 20-30 minutes before removing from the pan to cool completely.