Cake:

Preheat oven to 180*C or 350*F. Grease and line a 21cm loose-bottomed round cake tin.

Cream butter and sugar until light and fluffy, then beat in the eggs one at a time, adding a spoonful of the potato flour with each egg.

Gently mix in almonds, lemon zest and juice, and lavender flowers.

Pour the batter into the prepared tin and bake  for 50-60 minutes, until risen and golden, and a toothpick inserted into the cake comes out clean. Remove from the oven and leave in the tin to cool.

Once cold, remove from the tin and place on a serving plate. 

Icing and Decoration:

Mix icing sugar and lemon juice to give a smooth, runny icing. Pour over the cake and allow to set slightly.

Decorate with lavender flowers if desired.