Preheat the oven to 160°C, gas mark 3 and grease and line a 23cm round cake tin with baking parchment.
Place the eggs and caster sugar into the bowl of a stand mixer and whisk on a high speed for 8-10 minutes, or until tripled in volume.
Meanwhile, heat the butter, milk and vanilla paste in a saucepan over a low heat until the butter has melted and the mixture is steaming.
Whisking all the time, carefully pour the hot milk mixture into the eggs, aiming around the edge of the bowl. Sieve the flour and baking powder over the top and then fold in. The mixture will be quite runny.
Crush the raspberries to a paste with a fork. Pour the cake mixture into the lined tin and gently ripple half the crushed raspberries through the batter. Bake for 50-60 minutes or until risen, golden brown and a skewer inserted into the centre comes out clean. Allow to cool completely.
Whip the cream with the icing sugar into soft peaks and swirl through the remaining crushed raspberries. Pile over the cooled cake and top with fresh (if using) and freeze-dried raspberries before serving. This cake will keep refrigerated for 2-3 days, but is best served straightaway.