Preheat the oven to 175C/350F.
Line and grease 3 20cm/8 inch round cake tins.
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 ingredients 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.
Divide the mixture evenly into 3 bowls.
Add the cocoa to one, the walnuts to one and the poppy seeds to one. Stir each bowl until the new ingredient is mixed in.
Pour the cake mixture into the prepared tins. Bake for 15-20 minutes, or until cooked through.
Once the cakes have cooled completely remove them from the tins.
Place the Poppy Seed cake on a serving tray and cover with half the caramel cream.
Place the Chocolate Cake on top of the cream and spread the remaining caramel cream over the cake.
Place the Walnut Cake on top the cream and spread the ganache over the top of the cake.
Place the cake in the fridge for at least 1 hour before serving.