Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Grease the springform pan (20 cm Ø). Melt margarine. Puree silk tofu, tofu, sugar, vanilla sugar, lemon peel, starch and margarine with a hand blender until creamy.
Pour the tofu mixture into the mould and smooth it down. Spread the frozen berries over it. Bake in a hot oven for about 50 minutes.