Instructions

1. 1

   Set a square baking tin of about 16 cm into the basket empty and check the clearance. A large tin will not fit, and only if air is left all round does the heat travel past the tin.

2. 2

   Mix the plain flour with the sugar, the baking cocoa and the baking powder. Add the butter or margarine in pieces and the egg and quickly knead everything into a smooth shortcrust pastry.

3. 3

   Set a third of the dough aside for plucking. Press the rest of the dough into the tin, drawing it up the side to a height of about three centimetres.

4. 4

   Stir the low-fat quark until smooth with the sugar for the quark filling, the eggs, the vanilla custard powder, the melted butter or margarine and the vanilla sugar.

5. 5

   Spoon the quark filling onto the pastry base and smooth it. Pluck the reserved dough over it in coarse lumps.

6. 6

   Preheat the airfryer to 150 °C. At a higher heat the lumps of dough turn dark on top before the quark filling has set.

7. 7

   Set the tin into the basket in a single layer with space around it and stack nothing; only one tin will fit, and larger quantities are baked in two rounds. Bake at 150 °C.

8. 8

   Carry on baking at 150 °C until the quark filling only wobbles slightly in the middle and the lumps of dough look dry. The cake is not turned, as the soft quark filling would run out of the tin.

9. 9

   Switch the machine off and leave the cake inside to carry on setting, so that the middle firms up undisturbed.

10. 10

    Leave the cake to cool completely in the tin, then loosen it from the side with a knife, lift it out and cut it cold.