Grease a 9 inch pan with oil and preheat oven to 180°.
Beat the butter with sugar until smooth and creamy, then add the vanilla and mix. Add 2 egg yolks and beat well.
Add the flour, salt and baking powder to the mixture and mix. Followed by the milk and mix well.
Beat egg whites with cream of tartar (this should take a couple of minutes) then gently fold in the mixture into batter using a rubber spatula.
To prepare the topping, in a sauce pan mix the butter with the brown sugar and spices on medium heat, using a spoon mix to prevent it from being burnt until the sugar dissolves. Remove from heat.
Pour the caramel mixture into greased pan, then arrange the slices of the bananas on top. Next, pour the batter into pan and smooth the top.
Bake for 50-60 minutes or until a toothpick inserted comes out clean. Let the cake cool down for 10 minutes.