For the cherry sauce, drain the cherries, collect the juice and measure 200 ml of juice. Boil up the cherry juice and 100 g sugar. Stir starch and 3 tbsp water until smooth. Stir into the boiling cherry juice, bring to the boil and simmer for 2 minutes.
Fold in the cherries. Leave to cool.
Grease a square springform pan (approx. 24 x 24 cm; alternatively round, 26 cm Ø) with a high rim and dust with flour. Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer).
For the sponge mixture, cream butter and 250 g sugar with the whisks of the mixer. Stir in the eggs one by one. Mix flour, baking powder and lemon zest, stir in briefly. Pour the dough into the mould, add half of the cherry compote and smooth it down.
Bake in the oven for about 30 minutes.
Leave the cake to cool in the mould for about 10 minutes, remove from the edge and allow to cool completely. Whip cream with 2 tbsp. sugar, vanilla sugar and cinnamon until stiff. Dust the cake with icing sugar. Serve with the rest of stewed cherries and whipped cream.