Mocha maple walnut birthday cake- no refined sugar

Well here's that slice of virtual birthday cake I promised you! If you want to make a real one, here's how:
800g self-raising flour
400ml soya milk
300ml rice bran oil
200ml maple syrup
200ml "Sweet Freedom" (or fruit concentrate)
4-6 tabs Barleycup/ coffee substitute
8 tsps baking powder
Topping and filling:
100g walnut halves, chopped/ crushed- but quarter a few for decoration
200ml tahini
100ml maple syrup
100ml date syrup (I ran out of maple syrup; you could use 200ml and omit the date syrup)
2 rounded tabs cocoa powder
Warning: this is a BIG cake! The mixture fills 2 round 10" moulds. The maple syrup flavour is hard to detect, but you could tweak the proportions to get more of it in. (But watch the texture; I found my maple syrup was runnier than the Sweet Freedom or date syrup.)

• Mix all the dry cake ingredients together in a large mixing bowl
• Combine all the wet ingredients, whisking briefly to ensure the syrup combines well
• Beat wet into dry mixture
• Put into moulds and bake for about 30mins in an oven preheated to 180C, or until a thin skewer inserted comes out clean.
• Turn out onto a rack to cool
• Meanwhile, beat all topping ingredients together apart from the walnuts.
• When cake is completely cool, use half to sandwich the 2 cake halves together, along with the chopped walnuts.
• Top with the other half and decorate with quartered walnuts. (My writing does not come under the "no refined sugar" banner, as it was made with white icing sugar piped using the wring nozzle for writing!)