Preheat the oven to 375°F. Lightly grease an 8x12-inch jelly roll pan with spray oil and line with baking parchment. (I just cut a long strip of paper to cover the bottom and come up on opposite sides of the pan and leave the excess hanging over a little- this makes it easier to lift the baked cake out of the pan.)
First make the sponge: Blitz the sugar and coffee in a food processor for a few seconds to give a finely chopped mixture. This is really worth doing to help bring out the coffee flavor in the cake.
The only way to conquer the meringue mixture is with an electric mixer. Put the eggs, egg whites and vanilla seeds or extract in a large bowl and whisk for a good 3-4 minutes, until the eggs are mousse-like and have increased in size somewhat. Add the coffee and sugar mixture gradually in stages and keep whisking for another 3-4 minutes or so. To test to see if the eggs are whisked up enough, take a spoonful of the mixture and drop it back into the bowl. The egg mix should sit on the surface for a second before it disappears back into the mixture. This does take some time and it will never be as frothy as 3 eggs (the egg whites just don’t give it bulk) but it should still be really light and really fluffy.
Once the eggs are ready, lightly scatter the flour, baking powder, salt and sugar over the top and use a spatula to fold everything in very gently so as to retain all of that air that has been whisked into it. Gently pour the mixture into the pan from a low height so you don’t knock any air out, and level it out with a palette knife or the back of a spoon. Bake in the oven for 15-20 minutes or until springy to the touch. Then remove from the oven and leave to cool completely.
Meanwhile, mix the cream cheese and cream liqueur together in a small bowl until well-blended and lump-free. Sift the confectioners’ sugar in bit by bit, tasting as you go until it tastes just right for you. You may feel it does not need the extra sugar. However, if you are making this a nonalcoholic version, then just leave the cream liqueur out and definitely add the confectioners’ sugar. Finally, stir in the lemon zest, and cover and refrigerate until needed.
When the Swiss roll is almost cool, make the coffee sugar syrup: Put the sugar, coffee granules and 2 tablespoons of water in a small pan over low heat, stirring until the sugar and coffee dissolves. Then turn up the heat and let it bubble away for 30-60 seconds until syrupy, before removing from the heat.
Once the Swiss roll is cool, put a piece of baking parchment a little larger than the Swiss roll pan on the work surface and sprinkle the tablespoon of sugar evenly over it. Lift the Swiss roll out of the pan with the help of the overhanging baking parchment, and place it upside down on the sugar-sprinkled baking parchment. If the sponge is a bit stuck around the edges of the pan, just carefully run a small sharp knife around the inside edge to release it. Peel the paper off the base of the sponge, which is now facing upward, and brush the surface all over with the coffee syrup.
Then, using a palette knife or a large flat knife, spread the cream cheese mixture evenly all over the Swiss roll. When I did it, it felt as if I was spreading mayonnaise on a giant piece of bread! Scatter over the pecans and then, with one of the shorter sides facing you, roll the whole thing up, again quite tightly and not worrying about anything squidging out the sides. Dust the outside with confectioners’ sugar, if desired.
Place the Swiss roll seam side down on a serving plate and then serve! I have allowed 3/4 inch pieces per serving here, as it is quite rich.