Clean and wash gooseberries. Mix sauce powder with 50 g sugar and 6 tablespoons apple juice until smooth. Boil up the rest of the apple juice and gooseberries briefly. Stir in the sauce powder with a whisk, bring to the boil again briefly and allow to cool. Grind the pistachios finely and stir in. For the waffles, mix fat, 40 g sugar and vanilla sugar until foamy. Stir in the eggs one after the other.
Mix flour and baking powder. Alternately stir in with buttermilk. Preheat heart waffle iron and brush thinly with oil. Bake 4 golden brown waffles one after the other. Divide into small hearts and dust with icing sugar. Serve the groats and waffle hearts in portions