Preheat oven to 350 degrees F. Liberally grease a 9" loaf pan with cooking spray. I recommend using a metal or disposable loaf pan as I find glass ones usually cook at different times. If you only have glass, that's okay, but your bread may take less time. Place the pan on a baking sheet and set aside.
In a large bowl, mix together the softened butter and brown sugar with a spatula until combined. Mix in the eggs and yogurt, mixing well. Add in the banana, vanilla and molasses until blended. Mix in the spices, flour, baking soda, and salt until a thick but lumpy batter forms. Fold in the pudding mix (just the dry mix). Batter should be lumpy and do NOT overmix the batter, which leads to tough bread. Just make sure it's just about combined.
Pour the batter into the baking pan and smooth out the top. Bake uncovered for about 40 minutes, then tent the pan with foil and bake for another 25-35 minutes, checking at the 25 minute mark and adding time if needed. Bread will be done when a toothpick or cake tester inserted near the center comes out clean or with moist, not wet, crumbs. Cool completely.
To make the frosting: in a medium bowl, beat together the cream cheese, butter and vanilla extract until smooth. Beat in the heavy cream to combine, then the powdered sugar until a soft, thick icing forms.
Spread the icing on top of the bread and let set, about 10 minutes, before cutting into slices.