Peel and cut the apples into pieces.
Blend the apples into a smooth puree in a blender.
Add oat flakes, eggs, and baking powder to the puree. Mix until smooth.
Line an 18 cm (7-inch) baking pan with parchment paper.
Pour the mixture into the pan and decorate with cranberries and walnuts.
Bake at 180°C (356°F) for 40-45 minutes.
