Grease the bases of 2 springform pans (20 cm Ø). Whip butter and sugar until white-creamy. Stir in eggs one after the other. Mix flour with baking powder, sieve over the mixture and fold in. If the mixture is too firm, stir in a spoonful of milk.
Spread the mixture evenly on the two springform pans, smooth it down and bake in a preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 20 minutes (test with sticks). Leave to cool in the form for approx. 5 minutes, remove the cake bases from the forms, lift onto a cake rack and allow to cool
Whip the cream until stiff. Stir strawberry jam until smooth. Place a cake base on a cake plate and spread with cream. Spread the jam on top. Place the second cake base on top and sift icing sugar over it