Cream together eggs and caster sugar then add in one egg at a time and vanilla and beat until combined. Add in the self rising flour.
Pour the cake batter into the prepared tin and spread it evenly with a spoon (the batter will be thick)! Sprinkle the frozen berries over the top of the cake batter and then spread a layer of the canned pie apples. Set aside while you prepare the crumble.
In a bowl, use your fingers to rub the butter into the flour, sugar and oats mixture, until the mix resembles fine crumbs. Sprinkle an even layer over the prepared cake.
Bake for 60 minutes at 180 degrees C or until a skewer inserted into the middle comes out clean. Allow to cool in the tin for 30 minutes before transferring to a wire rack to cool completely. Serve warm or cold.