First, make the dough. Beat the egg and divide it into two parts. One part is for the dough and the other is for brushing.

Grease the springform pan and dust it with flour. You can also line the bottom with parchment paper.

Divide the dough into three equal parts. Use one part to cover the bottom of the pan. Use a second piece for the edges.

Roll each piece of dough out into a thin sheet so that you can easily line the tin.

For the base, take a sheet of dough that is slightly larger than the tin and cut out its shape with a sharp knife. Carefully roll the sheet around your rolling pin, then roll it out again over the tin. This will give you a neat base in one step.

For the edges, cut straight pieces that are slightly wider and taller than the edges of the springform pan. Press the edges firmly onto the bottom to prevent leakage. Then, cut away the excess dough with a sharp knife. Save the excess dough.

Next, make the cheesecake filling by beating the cream cheese with the sugar. Add the vanilla sugar, egg, and egg yolk, and mix until smooth. Pour the mixture into the bottom of the apple pie crust and smooth it with a spatula.

Peel and cut the apples into small pieces. Add the sugar, custard powder, and cinnamon, stirring until combined.

Spread the apple mixture evenly over the cheesecake filling and gently press it down. Do not press too hard; you do not want to push the apples too far into the filling.

If the filling does not quite reach the top edge, push the dough edges down to the apples.

Roll out the remaining dough, including the excess, into a thin sheet and cut it into strips about 1 cm wide.

Place the strips crosswise on the apple pie. Use extra dough strips to finish the edge all around. Brush the strips with half an egg and sprinkle cinnamon sugar over the lattice.