Preheat oven to 390 F. Pour corn syrup into a saucepan, add brown sugar, salt and butter. Warm over medium heat. Wait for the caramel to start foaming. Stir with a spatula and be careful not to burn it.
After 3-4 minutes from the beginning of the boil, remove the saucepan from heat. Stir the caramel for another minute, then pour into your 7" silicone round baking dish.
Put the peeled sliced bananas on top of the caramel. In a bowl, mix your all purpose flour and baking powder together. In another bowl, pour vegetable oil, vanilla and add sugar. Mix together.
Add eggs in with sugar and beat the ingredients for 2 minutes with a mixer. Add yogurt and stir again. Gradually add dry ingredients to mix slowly and make a thick dough.
Pour batter on top of bananas. Put the baking dish in the oven and bake for 45-50 minutes or until toothpick in center comes out with moist crumbs attached. (If the cake starts to brown too much on top, cover the baking dish with foil)
After the cake is baked so center has firmed but still very moist, remove and let it cool in the baking dish on a cooling rack for 15-20 minutes. Then turn it over onto a plate and remove.