Spray a 20cm x 30cm non-stick baking tray or brownie tin with low-calorie cooking spray (and line it with non-stick baking paper if you like).
Drain the chickpeas over a large bowl and measure out 200ml of the chickpea liquid (aquafaba), discarding any extra.
Pour the aquafaba back into the bowl and whisk using an electric hand whisk until soft peaks form (or use a stand mixer).
Add the sugar a little at a time, whisking constantly, until the mixture is thick and glossy.
In a large bowl, mix the yogurt, orange zest, lemon zest and juice.
Sieve the flour, bicarbonate of soda and baking powder over the aquafaba and gently fold in until just combined.
Then fold in the almonds, yogurt mixture and half of the blueberries, working quickly but carefully.
Pour into the prepared tin and level. Scatter over the remaining blueberries and bake for 25-30 minutes or until lightly golden (a skewer inserted into the middle of the cake should come out clean).
Leave to cool in the tin for 10-15 minutes before transferring to a wire rack.
When the cake is completely cool, mix together the icing sugar and 1 tsp cold water in a small bowl until you have a smooth icing, then drizzle over the cake. Cut into 18 slices and serve with the extra soya yogurt, and with the extra orange and lemon zest sprinkled over everything.
This will keep for up to 5 days in an airtight container.