Pre-heat the oven to 160C/fan. Grease a 20cm cake tin with a little butter and line the base with baking parchment. Sprinkle a tablespoons of desiccated coconut in the tin and shake and coat the sides. Set to one side.
Put the remaining desiccated coconut into a small pan and heat gently, stirring to toast until it’s a pale golden brown. Set to one side. Combine the flour and baking powder.
In a free standing mixer or in a large bowl using an electric hand held whisk beat the butter and sugar until really light and fluffy. Add the beaten egg, a tablespoon at a time, scraping down the sides a few times, between additions. Once all the egg has been added, add the flour in three additions, folding as you go. On the second addition pour in the desiccated coconut and coconut milk. Once all the ingredients are incorporated transfer to the prepared tin. Top with the blueberries. Bake in the centre of the oven for 35-40 minutes if using fresh blueberries, 60-68 minutes if using frozen. To check if the cake is done insert a cocktail stick in the centre of the cake, it should come out clean.
Cool in the tin on a wire rack for 10 minutes, then remove from the tin and cool for a further 15 minutes. Dust with icing sugar. Serve warm with Greek style yogurt or creme fraiche