I've made this before but it's worth revisiting because it's an impressive upside-down cake - bananas love to be caramelised. 

Caramel topping:
50g butter or dairy-free spread, melted
1/2 c firmly packed brown sugar
2-3 large bananas, sliced on an angle

Cake batter:
125g butter, softened (I used dairy-free spread this time)
3/4 c organic cane sugar
1 very ripe banana, mashed
2 eggs
1 tsp vanilla extract
1 tsp ground cinnamon
1/2 tsp ground nutmeg
2 c self-raising flour (I used spelt and increased baking powder to 2 tsp)
1 tsp baking powder
2/3 c milk (I used rice)

Preheat oven to 180C. Grease and line a 22cm spring-form cake tin with tight-fitting base. To make topping mix melted butter and sugar and spread into base of tin. Cover evenly with sliced bananas.

Cream butter and sugar in a bowl until pale. Sift flour and baking powder with spices and stir into creamed mixture, alternating with the milk and mashed bananas.

Spread cake batter over bananas. Place a tray under the tin to catch any syrup that may seep out. Bake for 50-60 mins or until a skewer inserted into the centre comes out clean.

Remove from oven, loosen edges of cake and remove spring-form surround. Immediately invert the cake onto a serving plate and carefully remove base of tin and lining while hot or the caramelised sugar will stick to the tin.

Best served on the day it is made. Lasts well for 2 days but is best heated to serve warm and with a dollop of cream.