Preheat the oven to 160ºc fan and line a 9x13" traybake tin
Beat together the butter and sugar until fluffy
Add the eggs, flour and mix until smooth
Fold through most of the raspberries and white chocolate chips
Top tip - coat the raspberries in flour to stop them sinking
Pour the cake mix into the tin
Sprinkle over the last few raspberries and white chocolate chips
Bake in the oven for 40-45 minutes and then cool fully
Beat the butter on its own until smooth
Add the icing sugar and mix, and then add the white chocolate and mix again
Spread over the sponge and then decorate with the raspberries, chocolate and freeze dried raspberries
