Pre-heat the oven to 160°C (320°F). Prepare your cake tin/s by lightly greasing with butter and dusting with flour. 

For the cake, beat the butter, lemon zest and sugar together until light and fluffy. Beat in the eggs one at a time, mixing well after each addition. Fold in half the flour and half sour cream, then stir in remaining flour and remaining sour cream until smooth.

Spoon the mixture into the prepared cake pan (or divide between individual tins) and bake a large cake for about 1 hour 20 minutes and for smaller cakes, around 25 minutes. Test the cake/s are ready by inserting a skewer into the center - when it comes out clean, it is cooked. Note: Cake/s should be slightly spongy when the center is gently pressed. While the cakes are baking, make the syrup and frosting.

For the syrup, mix all of the ingredients together in a bowl and whisk well until all the sugar has dissolved. Set aside.

For the frosting, beat the butter on a medium speed for a full 5 minutes. The butter needs to be pale and aerated. Add the icing sugar little by little, beating well after each addition to ensure the icing sugar dissolves and the frosting isn't grainy. Add the vanilla paste, sour cream, lemon zest and salt and beat until fully incorporated. Set aside in a cool place, but not the fridge (otherwise the butter will harden).

When the cakes are cooked remove from the oven. While still in the tin, poke several holes into the cake/s with a skewer. Pour the syrup over the hot cake/s and allow to sit in the tin for 10-15 minutes before transferring to a wire rack.

When completely cool ice with the sour cream frosting and decorate with the freeze dried raspberries and edible flowers.