1 Preheat the oven to 180c/Fan 160c/ Gas Mark 4.
2 Grease and line 1 x 16cm deep cake tin and 1x 23cm deep cake tin.
3 Weigh the eggs in their shells then measure out the same weight of butter, caster sugar and self-raising flour.
4 Beat the butter and sugar together in a stand mixer or with a hand whisk until really light and fluffy. Beat the eggs in a jug, and gradually add them to the butter, as you whisk, adding a spoonful of flour to stop it curdling.
5 Add the rest of the flour then stir in the lemon zest, poppy seeds and cordial.
6 Spoon 1/3 of the cake mixture into the smaller tin then spoon the remaining 2/3 into the large tin. Smooth out and bake in the middle of the oven for 60-85 minutes (the small cake will be ready after about 1 hour) until risen and golden and a skewer inserted into the middle comes out clean.
7 Leave to cool in the tins for 10 mins then turn out onto wire racks to cool completely.
8 To crystallise the rose petals, brush each petal with beaten egg white and pop into a bowl of caster sugar, turning until coated. Shake off any excess and leave to dry on a wire rack. The crystallised petals will keep for 24 hours in a dry cool place, they can be left on the decorated cake for up to 8 hours.
9 Beat the butter until really light then gradually add the icing sugar until you have a stiff butter icing. Add the cordial and 2-3 tbsp of boiling water and beat until light, fluffy and smooth.
10 Use a serrated knife to split each cake in half horizontally. Spread a 1cm thick layer of buttercream inside the cakes and sandwich them back together.
11 Place the large cake on a cake stand and use a palette knife to spread an even 1cm thick layer of icing over the sides and top of the cake, smoothing it as you go.
12 Place the smaller cake on the thin cake board and cover the top and sides with buttercream in the same way.
13 Push the 4 dowel rods into the cake, in a square in the middle. Mark on them the top of the cake line with a pencil. Remove the rods and cut to length then push back into the cake. Sit the little cake on top of the big cake, with a little blob of icing to secure it.
14 With a palette knife use a little more icing to smooth over the seam between the two cakes. The cake is now ready and can be stored in a cool place (but not the fridge) for 24 hours. When ready to serve, scatter over the crystallised rose petals.
Recipe courtesy of Belvoir