Preheat oven to 350F/180C. Butter a 9×5-inch loaf pan.
In a medium bowl sift together flour, baking soda, cinnamon and salt. Set it aside.
In a stand mixer fitted with the paddle attachment, beat together butter and sugar on medium speed for 3 minutes until light and fluffy. Scrape down the sides and the bottom of the bowl as necessary. On medium speed, beat in the eggs one at a time, beating well after each addition. Then beat in mashed bananas and vanilla extract. With the mixer on low speed, add half of the dry ingredients and beat just until combined. Add the yogurt and beat until combined. Add the other half of the dry ingredients and beat slowly or fold by hand only until combined. Do not overmix – the less you mix, the lighter the cake will be. Fold in chocolate chips.
Pour batter into prepared loaf pan and bake for 50-60 minutes until a toothpick inserted into the center of the cake comes out clean or with just a few moist crumbs. Let the cake cool for 10 minutes on a wire rack, then turn it out from the pan and let it cool completely.
The bread can be kept, tightly covered, at room temperature for 3 days or in the fridge for 5 days. Bring to room temperature before serving. It can also be frozen for up to 2 months. Thaw it on the counter, still covered, or overnight in the fridge.