1. Preheat the oven to 175C fan-forced (195C conventional). Grease and line the base and sides of a 20cm round cake tin. (You could also use a square or a bundt tin. If using a bundt tin, grease with butter, then dust with flour.)

2. Combine the corn kernels and milk (or coconut milk) in a deep bowl and use a hand-held stick blender to blitz until you have a fine puree. Set aside.

3. Sift the flour, baking powder and salt into a medium bowl, then add the polenta and coconut.

4. Place the butter, sugar and zest in the bowl of a cake mixer fitted with the paddle attachment and beat until pale and creamy. Add the egg yolks, one at a time, beating well after each addition and scraping the bowl with a silicone spatula from time to time to ensure batter is evenly mixed, then add the corn and milk mixture. Mix on low speed until combined, then add dry ingredients and mix until just combined – it might look a bit curdled at this stage; this is normal.

5. Using a hand-held whisk or the cake mixer, whisk the egg whites until soft peaks form.Fold one-third of the beaten egg whites into the batter to loosen it, then fold in what's left in two batches. Be gentle but thorough – you want the egg whites to be fully incorporated, but don't over-mix the batter as this will result in a dense cake.

6. Scrape the batter into the prepared tin and bake for 1 hour, or until a skewer inserted into the middle of the cake comes out clean (allow the cake to bake undisturbed for the first 45 minutes before checking). Remove from oven and cool in the tin for 30 minutes before turning out onto a wire rack to cool completely.

7. Sieve some icing sugar over the top of the cake and serve with fresh blueberries and a dollop of plain or coconut yoghurt.

Tip: Out of season, you could use defrosted frozen corn kernels or tinned corn; if using tinned corn, reduce the sugar to 150g and increase the baking time by 30 minutes, to account for its extra moisture and sweetness.