Whisk the eggs with the sugar for 10 minutes until they are thick. Sift over the flour and cocoa powder and gently fold them in, along with the measured hot water.
Grease a 33 x 23 cm (13 x 9 inch) Swiss roll tin and line with nonstick baking paper. Pour the mixture into the tin and bake in a preheated oven, 220°C (425°F), Gas Mark 7, for 8–10 minutes until risen and just firm.
Sprinkle a large sheet of nonstick baking paper with sugar. Upturn the cake on to the paper. Carefully peel off the lining paper. Use a sharp knife to trim off all the crisp edges.
Cut the cake in half, to make 2 long strips, then cut each of these strips into 3 pieces. As you cut the cake, cut the nonstick baking paper underneath as well and use a ruler to make sure all the strips are an equal width. Spread each piece of cake with 1 tablespoon chocolate spread. Roll up each cake and remove the baking paper.