Heat your oven to 170°C Fan/190°C/375°F/Gas Mark 5
Grease your swiss roll tin and line the base with a piece of greaseproof paper (baking parchment). Very lightly grease the greaseproof paper as well.
Separate your eggs and add the yolks to your mixing bowl along with your caster (superfine) sugar.
Using the paddle attachment, beat your egg yolks and sugar until light in colour and thick, this can take a few minutes. Small bubbles should appear on the surface when ready,
Sift your flour, baking powder and cinnamon.
Add half of your flour mixture to your beaten egg yolk mixture and beat in on a low setting.
Add the rest of your flour mixture and also beat that in.
Add your cooled coffee mixture and beat in on a low setting.
Scrape the sides and base of your bowl with your spatula to ensure all of the mixture is incorporated.
Turn up the mixer setting and beat the cake batter on medium-high for about 10 seconds. It will be quite a stiff mixture at this point.
Beat your egg whites until they form soft peaks.
Carefully fold your beaten egg whites into your cake mixture until just incorporated. When ready the mixture should be caramel coloured and quite frothy. Do not keep folding once mixed in otherwise air will be knocked out of your batter.
Pour your swiss roll cake batter into your prepared tin making sure it is spread out evenly into the corners. Hold your tin to tip the mixture towards the sides and corners and then use a palette knife to gently spread it evenly out.
Bake in the centre of your preheated oven for approximately 10 minutes. The swiss roll is ready once the centre bounces back when gently pressed and the cake is golden all over.
Whilst your swiss roll bakes, cut a piece of greaseproof (parchment) paper, that is about 2 inches larger than your swiss roll tin on all sides and quite liberally sprinkle over some golden caster sugar.
When your swiss roll is baked, stand the tin on its long side at a right angle on the edge of your prepared piece of greaseproof paper and in one swift movement tip your swiss roll out onto it.
Next, starting at one of the two shorter ends of your swiss roll. start to tightly roll your cake up, keeping the greaseproof paper within the roll.
Leave your rolled up swiss roll to cool fully.