batter:
90 g butter, soft
50 g sugar
2 eggs
100 g chocolate, 75%, melted
140 g flour
1/2 ts baking soda
1/2 ts baking powder
1 pinch of salt
100 g yogurt
100 g elderberry syrup (or mashed compote)
filling:
250 g elderberry syrup (or mashed compote)
agar powder for 250 ml liquid (or use more for a firmer filling)
500 g mascarpone
fruit mirror:
250 g elderberry juice (or strained juice from compote)
agar powder for 250 ml liquid
Mix elderberry syrup with yogurt, set aside. Whisk butter and sugar. Add eggs, one after another, and whisk until the mixture increases in size and becomes pale. Stir in the chocolate. Alternating add flour and yogurt mixture, stirring just briefly. Fill the batter into a greased springform pan (24 cm), flatten the surface and bake at 175 deg C for 20-25 minutes. Let cool completely before filling and coating it.
For the filling, bring the syrup to a boil, add agar and cook for 2 minutes, constantly stirring. Let cool, but not harden, then add mascarpone. Refrigerate the cake after filling and coating it.
For the mirror, bring the juice to a boil, add agar and cook for 2 minutes, stirring constantly. Let cool a few moments, then pour over the cold cake, beginning from the center.