Preheat oven to 180° C. Line a 16 cm springform cake tin with baking paper.
Mix 10 g of ground chia seeds with 50 ml of water. Stir and let it rest for 2-3 minutes to thicken.
In a large bowl, mix together the dry ingredients: teff flour, brown rice flour, ground almonds, tapioca flour, coconut sugar, finely chopped walnuts, raisins, baking powder, gingerbread spice mix or cinnamon and just a pinch of a baking soda.
Add rice milk, coconut oil, and chia mixture to the bowl with dry ingredients. Mix with a hand mixer for a minute or two until all is well combined. Adjust sweetness if needed.
Mix grated apples into the cake batter. You need to drain apples really well and squeeze out any excess water before adding them to the better or the cake will be too moist.
Pour the batter into the prepared cake tin.
Scatter a handful of fresh blueberries on top of the batter (optional).
Bake for approx. 40-45 minutes.
Remove from the oven and let it cool down.
Lightly dust it with powdered sugar or powdered xylitol.
Sprinkle with finely chopped walnuts.