Preheat the oven to 180°C.
Grease and line the base and side of a 26 cm springform cake tin.
Layer the apple slices in the prepared tin so they come about
two-thirds of the way up the side. Sprinkle the cinnamon sugar
over the apples.
Make a batter by beating the eggs and sugar until light and
fluffy. Add the oil and vanilla and beat well, then stir in the
flour. Spoon the batter on top of the cinnamon-covered apples
and sprinkle with extra cinnamon sugar.
Bake for 1 hour 20 minutes, or until a skewer comes out clean when
inserted into the cake. Cool in the tin. Serve warm with cream
or ice cream.
Note: To make cinnamon sugar to keep in your pantry, mix 2 tablespoons ground cinnamon with 1 cup caster (superfine) sugar