Preheat the oven to 350.
Using a mixer with a paddle attachment cream sugar and butter until light and fluffy. In a separate bowl combine flour, salt and baking powder. Set aside. Add eggs one at a time to sugar mixture ensuring each egg is incorporated. Add the mashed banana and combine. Combine milk, yogurt and vanilla extract to a medium bowl. Slowly add half flour and then half yogurt mixture to mixer mixing well after each addition. Add remaining flour and yogurt mixture to mixer combining well and scraping down sides if necessary.
Spray bundt an with cooking spray and dust with flour. Rotating pan to ensure even coat of flour is throughout pan. Turn pan upside down to remove any leftover flour that may have accumulated in the pan. Pour batter into prepared pan and tap on counter to remove any air bubbles. Bake in oven 1 hour to 1 hour and 10 minutes or until done. If you insert a toothpick into the middle of the cake and it comes out clean then the cake is done.
