Preheat the oven to 175C/350F.
Line and grease a 20cm/8 inch round cake. A spring form tin is best as it will allow for easy serving at the end.
Place the egg whites into the clean bowl of a kitchen stand mixer fitted with a whisk attachment. Whisk the egg whites on medium/high until soft peaks form. Slowly add the maple syrup, 1 tablespoon at a time, until large peaks have formed, continue whisking on medium/high and add the vanilla extract. Add the egg yolks, one at a time. Only add the next yolk when the previous one has been fully incorporated. Whilst still whisking, pour the milk into the egg mixture.
In a separate bowl, lightly whisk the coconut flour and baking powder together. Ensure that the coconut flour has no lumps in it. Turn the whisk to low and add the flour mixture. (If you keep it on high then you will most likely end up wearing the flour). Once incorporated, return the whisk speed to medium/high to fully mix all the ingredients.
Pour the cake mixture into the prepared tin and bake for 14-16 minutes, or until cooked through.
Remove from oven and allow to cool in the tin.
Ice Creams (the same instructions apply for each flavour):
Place the frozen fruit and the cream in a blender and process until smooth and combined. (if you are not using it in this cake then eat it now!!!)
How to make the layers
Take the cooled cake and leave it in the tin. Line the sides of the tin with baking paper or cling wrap.
Make and then immediately pour the Blueberry Ice cream over the cake. Cover the tin with wrap and place in the freezer for 2 hours to set. After 2 hours make and then immediately pour the Mango Ice cream over the cake. Cover the tin with wrap and place in the freezer for 2 hours to set. After another 2 hours make and then immediately pour the Strawberry Ice cream over the cake. Cover the tin well with wrap (2 layers is best and right on top of the ice cream) and place in the freezer for at least 6 hours to set (it can be left overnight.
Take the Fruit Ice Cream Cake out of the freezer at least 20 minutes before serving. It will be quite firm (as the berry ice cream layers set icier than the mango) so using a hot knife to slice the cake can be helpful.
Top with cut fruits if desired.
The cake will keep, covered, in the freezer for up to 1 week but the ice cream layers may become icy over that time.