Let's peel the apples and slice them thin. Place the biscuits on the bottom of the rectangular cake mold so that the tray is invisible and place the apples on top.
Sprinkle cinnamon on apples and pour walnuts.
Let's make the cake dough. Beat the sugar and eggs in a bowl and add the oil, flour, vanilla and baking powder.
Mix well and pour on the apples.
Bake it in a heated oven at 175 degrees.
Sprinkle powdered sugar on top of the baked and cooled cake.
If you want to serve as square cake slices, slice 7 times. (or smaller) Enjoy your meal!