My friend CL came over to bake with me. We initially wanted to bake a strawberry shortcake for her husband's birthday, however, as the sponge did not turn out well, we eventually only managed to bake this banana walnut muffin. The funny part is, both of us remembered that the recipe requires yoghurt instead of sour cream and both of us bought yoghurt. We did not manage to find sour cream at the supermart opposite my place and hence we decided to make do with yoghurt. The turnout was surprisingly very well done. I am happy with the results - it is soft and moist. Brought some of the muffins to my girls' school for the teachers and they love it. It turned out to be 'good' mistake.