For the base: Preheat oven to 180 °C (convection oven).

Insert the mixing attachment into the mixing bowl. Add egg whites with a pinch of salt and half of the powdered sugar and whip without measuring cup for 7 minutes / speed 3.5. Remove the whisking attachment and pour the beaten egg whites into a large bowl.

Replace the whisking attachment. Cream the butter with the remaining powdered sugar, QimiQ cream base, cooking chocolate and vanilla sugar for 3 min./60°C/step 1.5 until smooth. Finally add the egg yolk.

Add the flour, baking powder and hazelnuts to the mixture in the mixing bowl and fold in for 5 sec./stage 3.

Get the mixture out of the mixing bowl and fold into the beaten egg whites.

Spread the mixture on the baking sheet and bake in a preheated oven for about 35 minutes. Let cool.

Divide the cake base in half. Spread one part with half of the jam. Place the second part on top and spread with the remaining jam.

For the chocolate glaze: Add the chocolate to the mixing bowl and grind for 6 sec./speed 8.

Add butter and heat for 4 min./50°C/step 2.

Add milk and stir for 10 sec./speed 4.5 until smooth. Remove mixing bowl lid, allow glaze to cool until Thermomix temperature indicator has dropped to 37 °C, stirring occasionally with spatula during this time.

Then heat again for 2 min./50°C/step 3. Empty the glaze over the base in one sweep, spread quickly and allow to dry.