To make the sponge, set the shelf in the lowest position in the oven and pre-heat it to 180°C (350°F/Gas Mark 4). Grease the tin and line the bottom with a disc of baking paper.
Beat the eggs with the sugar in the bowl of a stand mixer fitted with the whisk attachment until pale and frothy. The egg mixture should reach the ‘ribbon stage’, i.e. the mixture should fall from the whisks in continuous ribbons, leaving a trail on the surface of the batter that does not disappear. This will take 10-15 minutes with the mixer at high speed.
Meanwhile, warm the milk and butter in a small pan over low heat until just simmering. Remove from the heat and incorporate the coffee.
Sift the flour, baking powder and salt into a bowl and gently fold it into the egg mixture in 3 stages, using a silicone spatula. Put 3 large tablespoons of the mixture in a bowl, then add the milk and coffee mixture and whisk to combine. Slowly pour this mixture into the rest of the batter, folding it in delicately with the spatula until fully combined.
Pour the batter into the tin and bake for 45 minutes or until a skewer inserted into the centre of the cake comes out clean and dry.
Leave to cool in the tin for 10 minutes, then remove the ring and transfer the cake to a cooling rack to cool completely.
To make the filling, add 2 tablespoons of soluble coffee to hot milk and mix until fully dissolved before incorporating the milk. If you prefer a sweeter cream, use 125g sugar instead of 110g. For a moreish boozy kick, add 2 tablespoons of sambuca to the cream while it is still warm. The filling should be prepared at least 1-2 hours before it is needed to give it time to cool to room temperature.
While the cake cools, you can make the glaze. Prepare a simple coffee glaze by mixing the icing sugar with 2 teaspoons of espresso. This sugar-to-coffee ratio will give you a rather thick glaze, suitable for piping. If you are drizzling it with a spoon, you might need to add a third teaspoon of espresso to achieve a thinner texture. Line the surface of the glaze with clingfilm and set it aside for later.
Now its time to assemble. Once the sponge has cooled completely, slice it in half horizontally to divide it into 2 discs of about equal thickness.
Secure the bottom disc of sponge to a serving plate with a small dollop of cream. Spread the coffee cream over the bottom disc of sponge and level it out with a spatula or a spoon. Top with the remaining disc of sponge and press it down gently.
Drizzle the coffee glaze over the cake with a spoon or with a small piping bag fitted with a 2mm diameter nozzle. Store in the fridge for up to 2-3 days.