1Preheat oven to moderately low, 160 C. Lightly grease and line a 20-cm cake pan with baking paper, leaving a 2-cm overhang.
2Sift flour and cocoa together into a bowl. In a saucepan, heat buttermilk with coffee powder and vanilla, on low, stirring until dissolved.
3Stir sugars, apple sauce and buttermilk mixture into the flour mixture until it’s well combined.
4In a clean bowl, using an electric mixer, beat egg-whites until soft peaks form. Fold into flour mixture with choc chips. Pour into pan.
5Bake 40 to 45 mins until cooked when tested. Cool in pan on a wire rack about 15 mins, before lifting out onto rack to cool.