Wash the potatoes and cook for about 20 minutes. Drain, rinse with cold water and let cool a little. Meanwhile drain the cherries and mirabelles and collect the cherry juice.
Bring to the boil with 1 tablespoon of sugar, lemon zest and lemon juice. Stir 1 tablespoon of starch in a little cold water until smooth and stir into the cherry juice. Bring to the boil again and fold in the fruit.
Wash the raisins, dab dry and soak in rum or apple juice. Peel the warm potatoes and press them through the potato press or mash them finely with a masher. Drain the raisins.
Knead curd, remaining sugar, remaining lemon peel, salt, eggs, flour, remaining cornstarch, baking powder, mashed potatoes and raisins with the dough hooks of the hand mixer. Form small cookies (approx. 7 cm Ø) with slightly floured hands.
Fry in hot fat (180 °C) until golden brown. Drain on kitchen paper. Sprinkle with icing sugar and serve with some compote. Serve the rest of the compote separately.