Pre-heat your oven to 180°C / 160°C fan assisted / gas mark 4 / 350°F.
Grease and line 2 x 8 inch cake tins (4 inch depth) with baking parchment paper.
Combine the ground chia seeds and water in a small bowl. Stir well to mix, making sure the chia seeds are fully immersed in water. Allow the mixture sit for about 5-10 minutes until it thickens to a gel-like consistency.
In a large bowl, whisk together the white rice flour, almond flour, baking powder, bicarbonate of soda, and salt. Set aside for a moment.
In another large mixing bowl, whisk together the olive oil, caster sugar, coconut yoghurt, apple cider vinegar, lemon zest, and vanilla extract until well combined and slightly creamy.
Add the chia seed mixture to the wet ingredients and mix well until fully incorporated.
Pour the flour mixture into the wet ingredients and mix again until everything is well combined.
Pour the batter into the prepared cake tins and smooth the top with a spatula. For a really even surface grease your hands slightly with some extra oil and use them to smooth out the tops of the cake batter.
Bake for about 40-45 minutes, or until a toothpick inserted into the centre of the cake comes out clean.
Transfer to a wire rack to cool completely before filling with the jam and cream.