Line two 20cm springform cake tins with baking parchment. Whisk the eggs with the sugar in a bowl for 5 mins or so until thick and aereated. Slowly pour in the olive oil, whisking continuously, then pour in the honey and vanilla, and whisk again to combine.
Heat the oven to 180C/160C fan/gas 4. Combine the flour, baking powder, spices and a pinch of salt in another bowl and mix. Lightly sieve this into the wet mixture, fold in, then add the walnut flour, little by little, until combined. Fold through the chopped walnuts and divide between the tins.
Bake for 25-30 mins until a skewer inserted into the middle comes out clean. Remove and leave to cool in the tins.
To make the candied walnuts, tip the walnuts onto a baking tray and roast in the oven at 200C/180C fan/gas 6 for 4-5 mins until crisp. Meanwhile, combine the sugar, molasses and 20ml water in a saucepan, and set over a medium heat until the mixture turns a deep caramel colour (around 3-4 mins). Turn the heat down low, then add the nuts, stirring constantly until completely coated. Remove from the heat and tip out onto a layer of baking parchment to cool.
To make the frosting, beat together the icing sugar and cream cheese until well combined and smooth (the icing will get thinner before it thickens, so continue to whisk for 2 mins), then briefly stir through the molasses to create a ripple effect. Spread half of the frosting on top of one of the cake layers, then sandwich with the other. Top with more icing, the pomegranate seeds and candied walnuts. Serve cut into slices. Will keep chilled in an airtight container for up to three days.