Line three trays with baking paper. Preheat the oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Cream butter, 125 g sugar, 1 packet of vanilla sugar and 1 pinch of salt with the whisks of the mixer.
Stir in the eggs one by one. Mix flour, baking powder and pudding powder. Stir in little by little. Colour dough red with food colouring.
Using a tablespoon, place approx. 40 heaps (each approx. 4.5 cm Ø) of the dough on the trays. Leave enough space between the heaps, as they will come apart during baking. Bake one after the other in a hot oven for 8-10 minutes.
Carefully remove from the baking paper and let it cool down on a cake rack.
Wash the lemon hot, dry and finely grate the peel. Mix lemon zest with mascarpone, quark, 100 g sugar and 1 sachet of vanilla sugar. Pour cream in portions into a piping bag with a perforated spout.
Spray the smooth side of one half of the cookies in a spiral and smooth the edges with a knife. Place the remaining biscuits on top as a lid and press down gently. Keep Whoopies cold for about 1 hour.