Preheat the oven to 180°C~356°F. Then grease and line a baking tin. I used 9' round baking tin.
Melt the butter and allow it to cool for 10 minutes. In the meantime beat the eggs, sugar and vanilla until frothy. Add the gluten free flour, baking powder, corn starch, rainbow chips, a pinch of salt and water. Mix until well incorporated.
Pour the batter in the baking tin. Bake for about 30-35 minutes or until a toothpick in the centre comes out clean. Allow the cake to cool down (about 30-40 minutes).
In the meantime, whisk the whipped cream, sugar and vanilla together until smooth. Add the strawberry essence. Set aside ⅓ of the whipped cream (to coat the cake). Melt the gelatine and pour slowly into the whipped cream. Mix until well incorporated.
In a small bowl, mix 2 tablespoons brown sugar, 1 teaspoon vanilla essence and 100 ml boiled water. Stir until the sugar is dissolved.
Using a sharp knife, cut the cake, horizontally, into two layers. Place one of the layers on a cake stand or plate and drizzle with the sugar syrup lightly. Then spread the whipped cream with gelatine on the top. Place in the fridge for 30 minutes or until it sets.
Then place the second layer, brush sugar syrup on the top and use the remaining cream to coat the cake all over. Decorate with fresh strawberries (and blueberries - optional) and sprinkle some rainbow chips on the top. Refrigerate for couple of hours or overnight.
Enjoy!