Preheat oven to 190 C / Gas 5. Grease 3 (15cm) cake tins then line with baking parchment.
Into a mixing bowl combine the flour, caster sugar, baking powder and bicarb (sifting is not necessary). In a separate bowl whisk together the oil, water and vanilla extract.
Make a well in the centre of the dry ingredients. Pour the wet ingredients into the centre, and mix until well with a wooden spoon until well integrated, about 3 to 5 minutes.
Divide the cake mixture into 3 equal parts and pour in the prepared cake tins. Let stand for at least 15 minutes. This step is essential for the gluten free flour to soak well.
Bake in the preheated oven for 45 minutes. Once ready, remove from oven and let cool for 5 minutes before turning out on a rack. Leave to cool completely before filling and decorating.
For the filling:
Place the coconut cream in a mixing bowl and chill in the freezer for 5 minutes. Remove and add the vanilla extract. Using a handheld whisk, gradually add the sugar until stiff peaks form. Spoon the cream into a piping bag with a large nozzle.
To assemble the cake, place one of the sponge cakes on a serving plate. Pipe about half of the cream in concentric circles to cover the top of the sponge. Arrange half of the peaches over this first layer. Add the second cake layer and repeat, using up the remainder of the cream and peaches. Lightly dust the top of the cake with icing sugar and serve.