Nussecken, hazelnut and chocolate triangles

Heat the conventional oven to 180 °C. Line a 39 × 26 cm rimmed tray. For the base, weigh 125 g of butter and soften it, 100 g of sugar and 8 g of vanilla sugar. Reserve 175 g of butter, 130 g of sugar and 8 g of vanilla sugar for the topping. Mix the base portions with the eggs, add flour and baking powder, bring together without prolonged kneading and press into the tray. Spread the jam over the base without mixing it into the dough.

Melt the reserved 175 g of butter with the reserved 130 g of sugar and 8 g of vanilla sugar in a saucepan. Add hazelnuts and water. Stir over heat until evenly moist, about 5 minutes in total. Spread over the jam without disturbing the base.

Bake for 27 minutes at 180 °C, checking from 25 minutes for golden edges and a firmer centre. Cool for 10 minutes. Cut into 12 rectangles in a 4 × 3 grid, then halve each diagonally to make 24 triangles. Leave in the tray for a further 30 minutes, until completely cool.

Chop the chocolate and gently melt it over a water bath in a dry bowl, about 5 minutes, keeping the bowl clear of the water. Transfer to a tall container. Dip the cold triangle tips and set on baking paper. Allow at least 30 minutes to set in a cool room. Wait longer if still sticky.