Preheat oven to 350F. Butter a 9"x5" loaf pan.
In a medium bowl, whisk flour, salt and baking soda.
In a large bowl, beat butter and sugar until light fluffy, using a electric mixer, 3 minutes.
Add eggs, one at a time, beating well after each addition and scraping the sides as needed.
Beat in bananas, sour cream and vanilla.
Beat in flour mixture and chocolate on medium sped.
Pour the batter into the prepared pan.
Bake until the cake tester inserted in the center comes out clean, 50 to 60 minutes.
Let the bread cool in the pan for 10minutes, then remove onto a cooling rack to completely cool down.