Tri-Coloured Cupcakes

Name: Tri-Coloured Cupcakes
Prep time: 30 min
Cook time: 1 h 30 min
Total time: 1 h 30 min
Yield: 12 pieces
Ingredients: 70 g water; 20 g cocoa powder; ¼ tsp baking powder; 35 g unsalted butter; 15 g sunflower oil; 100 g sugar; 1 pinch fine sea salt; 50 g double cream; 1 large egg; 90 g plain flour; 130 g plain flour; 80 g sugar; 70 g milk; 50 g unsalted butter; 2 egg whites; 1 tsp baking powder; 1 tsp vanilla sugar; 1 pinch fine sea salt; 100 g fresh mixed berries; 150 g unsalted butter; 300 g icing sugar; 1 Tbsp vanilla sugar