Preheat oven to 350 degrees F (180 degrees C). Butter 10-inch (26 cm) springform pan (with a removable base)

In a large bowl combine the apple slices with lemon juice and cinnamon. Set aside until ready to use.

Combine flour, baking powder and salt into a medium bowl.

In another bowl cream together butter and sugar until well mixed. Beat in the egg yolks, sour cream, lemon zest and vanilla extract. Stir in flour mixture and mix until well combined.

Spoon the batter into the prepared pan. (Don't worry if it's thick just put dollops around the tin and smooth with a knife) Once that's done arrange the apple slices on top (or dump them on the top like I do lol). Bake for 30 minutes.

Whilst the cake is in the oven make the meringue by whipping the egg whites until foamy with a mixer. Gradually add the sugar whipping the whole time until it holds very stiff peaks.

Remove the pan from the oven and add whipped egg whites on top of the cake and bake for another 20 minutes or until golden brown.

Run a sharp knife completely around the inside edge of the pan. Let cool slightly at room temperature before serving. We like ours with a dollop of vanilla ice-cream.