Peel 2 ripe bananas, add to a bowl then mash with a fork.
Add 1 large egg, 150ml milk (any) & 1 tsp vanilla paste/extract. Mix well.
Blend 100g rolled oats in a food processor & add to the bowl. Add 100g self raising flour, then mix until combined.
Break up 6 custard cream biscuits into pieces, then stir into the batter along with 50g white chocolate chips.
Grease/line a cake or loaf tin, then spoon in half of the batter.
Swirl 75g custard into the batter, then add the rest of the batter over the custard.
Swirl another 75g custard on top, then scatter over 2 more custard creams (break into pieces).
Air fry at 170C for 30-35 mins. If you have a bake setting on your air fryer use this, otherwise the regular air fryer setting is fine. You can check if it is cooked by inserting a skewer/sharp knife into the centre which should come out clean.
Alternatively oven bake at 170C fan/190C for 35-40 mins.
Either serve immediately or allow to cool completely on a wire rack before storing in an airtight container.
