Remove the bananas from the freezer and put them in a bowl to thaw. They will leak sugar/syrup while thawing, so absolutely do not just put them on the counter.
Remove the butter and eggs from the fridge and let sit to reach room temp.
In the ramekin, mix the sour cream (or yogurt/dahi) with the baking soda using the small fork. Set aside for now.
In a mixing bowl (or with a stand mixer), cream the butter and sugar with the vanilla. Set aside the butter wrappers for now.
Use the butter wrappers to grease the baking pans, then discard the wrappers.
Incorporate all eggs to the creamed butter & sugar, but do not over-beat.
Mix flour and salt into the creamed butter-sugar-eggs.
Add the bananas, mix, then add the chocolate chunks (chips / shavings) and mix.
Finally, add in the baking soda & sour cream (yogurt/dahi) and mix until incorporated. (This goes in last to minimize how much it gets mixed, and therefore, how much CO2 you lose from the baking soda making bubbles in the sour cream.)
Bake at 350 F for about 1 hour, or until the batter is set in the center of the pan (usually a big crack forms down the middle as the loaf blooms). Remove a bit early for bread pudding style (my preference).
Remove and let cool. If underbaked for a bread pudding consistency, the center will collapse when cooling. If fully baked for a bread consistency, the center will stay risen.
Best served hot with butter, and maybe pudding, custard, or ice cream on top.