Berry Mousse Cake

I decided to do a new take on a recipe that I made a long time ago. A recipe that I actually won a prize for.

Ingredients:
For cake:
80g of butter
165g of sugar
2 eggs
1tsp of vanilla
1 cup of flour
1 tsp of baking powder
½ cup of buttermilk

For Port Syrup:
1/3 cup of sugar
1/3 cup of Port wine
1/3 cup of water

For Mousse:
250mL of heavy cream
2 egg whites
3 tbsp of sugar
500 g of berries
3 sheets of gelatine

For Decoration:
Berry syrup or jam