A family classic. You could decorate this roll with butter icing and use it for a Christmas log.
4 large eggs
100 g (4 oz) caster sugar
65 g (2½ oz) self-raising flour
40 g (1½ oz) cocoa powder
FOR THE FILLING
3 tablespoons blackberry jam
300 ml (10 fl oz) whipping or double cream, whipped
1 Pre-heat the oven to 220°C/Fan 200°C/Gas 7. Grease a 33 x 23 cm (13 x 9 in) swiss roll tin and line with baking parchment.
2 Whisk the eggs and sugar in a large bowl until the mixture is light and frothy and the whisk leaves a trail when lifted out. Sift the flour and cocoa into the mixture, carefully folding them in at the same time. Turn the mixture into the prepared tin and give it a gentle shake so that the mixture finds its own level, making sure that it spreads evenly into the corners.
3 Bake in the pre-heated oven for about 10 minutes or until the sponge begins to shrink from the edges of the tin. While the cake is cooking, place a piece of baking parchment a little bigger than the size of the tin on to a work surface and sprinkle it with caster sugar.
4 Invert the cake on to the sugared parchment. Quickly loosen the parchment on the bottom of the cake and peel it off. Trim the edges of the sponge with a sharp knife and make a score mark 2.5 cm (1 in) in from one shorter edge, being careful not to cut right through. Roll up the cake firmly from the cut end, with the parchment inside, and leave to cool.
5 Warm the jam gently in a small pan until it is of a consistency that is easy to spread. If it is too warm it will soak straight into the sponge. Carefully unroll the cooled cake. Remove the parchment, spread with jam and whipped cream and re-roll.
Read more: How to Prepare a Chocolate Rum Cake