Prepare the Cream: In a saucepan, combine milk, cornstarch, egg yolk, sugar, and vanillin sugar.

Cook over medium heat, stirring constantly, until the mixture thickens. Remove from heat and let it cool.

Prepare the Dough: In a bowl, combine flour, baking powder, and powdered sugar.

Add vegetable oil, eggs, and lemon zest. Mix until a smooth dough forms.

Fold in the chopped apricots.

Assemble the Cake: Spread half of the dough into the prepared baking dish.

Pour the cooled cream over the dough.

Cover the cream with the remaining dough, spreading it evenly.

Bake the Cake: Preheat the oven to 200°C (400°F) with both top and bottom heat on.

Bake in the preheated oven for about 20 minutes, or until the top is golden brown.

Serve: Let the cake cool before slicing and serving.