Divide the ricotta into 2 bowls, add 20 g (half) of icing sugar and vanilla extract to one, then add the remaining icing sugar and cocoa powder to the second one and mix both until smooth.
Mix the coffee with the Kahlua in a separate container.
Remove the paper mould from the panettone, place it horizontally and cut 1 cm thick round slices, then cut them into 4 quarters.
Line the basins with a slightly oversized cling film (this will aid the demoulding process)
Place the panettone pieces around the sides of the basins, overlapping slightly, then pour some coffee over it and press against the sides.
Spoon ¼ of the vanilla ricotta in the centre, then cover with a piece of panettone. Spoon ¼ of the chocolate ricotta and cover with panettone. The basin should be completely full to the edge.
Drizzle the top layer with some coffee before covering and placing in the fridge for a minimum of 4 hours (ideally overnight).
To serve, simply pull gently on the cling film and turn upside down in the serving plate.