Preheat the oven to 180°C. Grease the inside of the tart pan with a thin and even layer of butter (not listed). Then dust with a layer of cake flour (not listed).
Allow the butter to return to room temperature. Add the banana to a food processor and blend into a thick purée.
Sift together the cake flour and baking powder. Slice the banana for decoration into 1 cm slices and sprinkle with lemon juice.
[Caramel Sauce] Add the sugar and 2 tablespoons of water to a pan and put on a high heat. When the mixture turns brown, stop the heat, add 3 tablespoons of water and mix together.
Add the butter into a bowl and cream with a whisk. Then add the powdered sugar, brown sugar and salt and mix well.
Add the almond flour into the mixture and mix. Add the egg yolks a little a time and stir in after each addition. Pour in the banana purée and mix again.
Add the sifted cake flour and baking powder in 2-3 goes and fold in with a rubber spatula.
Pour the batter into the tart pan and flatten out the surface. Arrange the bananas from Step 3 on top and press them into the batter a little.
Bake for 25 minutes at 180°C. Then turn the temperature down to 160°C and bake for a further 10 minutes. Check to see if it's done by inserting a skewer into the center. If it comes out clean, it's ready!
Sift over some powdered sugar, pour over the caramel sauce and serve! Instead of making the caramel sauce yourself, you can also buy it at the shop.
This cake is okay just out of the oven but tastes much better after a day when the flavours have had a chance to settle.
Story Behind this Recipe
The banana cake that I ate in a cafe had a delicious flaky texture and wondered if I could recreate that at home. The cake I ate at the cafe came with caramel cream but I'm more of a caramel sauce kind of person.
If you don't have a food processor, you can mash the bananas up with a fork. When you are making the caramel, the mixture will sputter when you add the last lot of water, so be careful. Make sure to chill the sauce well once you've made it.