Cream together the butter, sugar and vanilla extract until pale and fluffy, then gradually beat in the eggs. Fold in the flour. Spoon half the mix into another bowl. Add the white chocolate chips to 1 bowl and the plain dark chocolate chips and cocoa powder to the other. Mix each until combined.
Grease a 23 cm (9 inch) dome-shaped daisy tin or heatproof bowl, then dust with flour. Spoon in the mixtures alternately, then run a knife through the mixtures to marble them. Make a dip in the centre and bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 1–1¼ hours. Cool for 15 minutes, then turn out on to a wire rack and cool for a further 30 minutes.
Boil the sugar and measured water in a pan for several minutes until the liquid becomes syrupy. Remove from the heat, then add the orange liqueur.
Knead the liquid glucose or orange liqueur and cocoa powder into the marzipan. Roll out two-thirds of the marzipan between 2 sheets of baking paper to a 40 cm (16 inch) circle, then mould large ripples across it.
Trim the cake base if needed and turn on to a serving plate. Spoon over the syrup and brush with warm apricot jam. Drape over the marzipan and trim off the excess at the base. Pat the sides to make an edge.
Roll out the remaining chocolate marzipan and cut 20 x 2.5 cm (1 inch) flower shapes. Reroll the trimmings and cut 3 larger but differently sized flower shapes and stack these on top. Arrange the small flowers at the base of the cake. Finish the topping with 1 white chocolate coffee bean.