Pre-heat oven to 200°C (conventional). Grease and line a 23cm round springform cake tin with baking paper.
Fit the metal bowl with the whisk. Add butter and sugar to the bowl. Mix using the EXPERT programme 1 min / speed 5/ 0°C with lid on.
Add the eggs. Mix using the EXPERT programme 30 secs / speed 5/ 0°C with lid on.
Scrape down the sides using the Magimix spatula. Add salt, vanilla, sour cream, flour and baking powder. Mix using the EXPERT programme 1 min / speed 5/ 0°C with lid on.
Add the crushed bananas. Mix using the EXPERT programme 1 min / speed 2A/ 0°C with lid on.
Spread cake batter into the prepared tin. Place sliced banana on top. Scatter with oats and coconut sugar.
Bake in the pre-heated oven for approximately 50 minutes to an hour until risen, golden and cooked through when tested with a skewer down the middle.
Remove from oven. Allow to cool in the tin for 10 minutes. Remove onto a serving plate and serve warm with creme fraiche or pure cream.
Regular Method
Pre-heat oven to 200°C (conventional). Grease and line a 23cm round springform cake tin with baking paper.
Place butter and sugar in the bowl of a stand mixer. Process on low-medium for a couple of minutes until light and creamy. Add the eggs one at a time while processing until the mixture is fluffy and voluminous.
Add the salt, vanilla, sour cream, flour and baking powder. Process for 30 seconds until smooth and thoroughly mixed.
Using a wooden spoon, gently fold through the crushed bananas.
Spread cake batter into the prepared tin. Place sliced banana on top. Scatter with oats and coconut sugar.
Bake in the pre-heated oven for approximately 50 minutes to an hour until risen, golden and cooked through when tested with a skewer down the middle.
Remove from oven. Allow to cool in the tin for 10 minutes. Remove onto a serving plate and serve warm with creme fraiche or pure cream.