Powder puffs are sometimes known as sponge kisses and should be soft to bite into. I tried one recipe that failed and then rang a friend who hails from the country who tracked down this, Aunt Peggy's recipe. Leave them for three hours in an airtight tin before filling with cream. From The Cook's Companion.
75g plain flour
¾ tsp cream of tartar
½ tsp bicarbonate of soda
3 eggs, separated
¾ cup castor sugar
stiffly whipped cream
Preheat oven to 210C (if using a fan-forced convection oven, 200C may be better) and line four baking trays with baking paper.
Sift dry ingredients, except sugar, three times.
In a separate bowl, beat egg whites to soft peaks, then gradually beat in sugar until mixture forms a glossy, stiff meringue. Add yolks one at a time.
Sift dry ingredients over mixture, then fold in very gently and thoroughly. Do not stir mixture after this point. It should be firm and when spooned onto trays should not settle or run. Quickly spoon heaped teaspoons of mixture onto prepared trays, well apart to allow for spreading. Cook for 5-7 minutes until sponge-coloured. Allow cakes to rest on trays for one minute, then, using a spatula, slip them onto a wire rack.
When cakes are completely cold, store in pairs in an airtight tin for at least three hours, then fill each pair with a good spoonful of lemon curd and whipped cream three hours before serving.
They will take about 30 minutes to soften. Dredge surface with icing sugar before serving.