Preheat oven to 350 degrees.
Start by combining the flour, baking soda, and salt. Set aside.
In another bowl, cream together the butter and sugar.
In yet another bowl, mash your bananas up.
To the butter/sugar mixture, add the bananas, eggs, and yogurt. Mix well!
Gradually stir in the flour, mixing well.
In a separate bowl, microwave (or melt on the stove) the chocolate. Add 3/4 cup of the batter to the chocolate.
Layer the batter and chocolate in a loaf pan and swirl with a knife.
Bake for 1 hour and 15 minutes. Pull out and let sit for 10 minutes before popping it out onto a wire rack and cooling completely.
Store in fridge and enjoy!