Raspberry Mascarpone Cake

Name: Raspberry Mascarpone Cake
Prep time: 40 min
Cook time: 30 min
Total time: 1 h 10 min
Cuisine: British
Ingredients: 100 g butter; 200 g caster sugar; 1 tsp pure vanilla extract or 1/2 tsp of vanilla paste; 3 medium eggs (separated); 200 g natural or greek yoghurt; 230 g plain flour (all-purpose); 2 tsp baking powder; 1/2 tsp bicarbonate of soda / baking soda; 1 pinch fine sea salt; 100 g fresh raspberries (fresh or frozen); 50 g caster sugar (4 tbsp); 2 tsp cornflour (cornstarch); 200 g white chocolate (broken up into small pieces); 250 g mascarpone; 100 g butter (room temperature); 100 g icing sugar (US powdered sugar); 125 g whipping cream; 25 g fresh raspberries (fresh for decoration)