1.Preheat oven to 180C or 160C fan. Lightly grease and line base and sides of a 26cm x 32cm swiss roll pan.
2.Using an electric mixer, beat eggwhites until firm but not dry. Add sugar, 1 tablespoon at a time, beating constantly until mixture is thick and glossy. Beat in egg yolks until just combined.
3.Meanwhile, finely sift cornflour, plain flour, spices and baking powder. Lightly fold into egg mixture with 1 tablespoon of honey, mixing gently until evenly distributed. Spoon into prepared pan, shaking gently to spread mixture evenly.
4.Bake for 20 minutes, until risen and firm when lightly pressed with a fingertip. Turn out onto a tea towel lightly dusted with extra sugar. Quickly peel off paper and trim edges. Roll up immediately in tea towel, starting from short edge. Set aside to cool.
5.Using an electric mixer, beat butter until pale and creamy. Add remaining honey and beat until well mixed. Add 2 tablespoons water and continue beating until mixture is smooth and creamy. Unroll cake and spread over filling. Roll up again and cut across into slices to serve.