Preheat the oven to 325°F.

In a large bowl, cream the butter and sugar together until pale and fluffy. Add the eggs one at a time, beating between each addition. Add the lemon zest, ground almonds and flours and beat to a smooth batter. Finally, add the lavender and stir through.

Spoon the mixture into the prepared loaf pan, spread level and bake in the preheated oven for 40 minutes. A skewer inserted into the middle of the loaf should come out clean. Remove from the oven and leave to cool in the pan for 30 minutes before turning out onto a wire rack to cool completely.

This cake is best eaten on the day of baking, but will keep for up to 4 days in an airtight container or frozen for up to 2 months.

*To make your own self-rising flour, combine 1 cup all-purpose flour, 1 teaspoon baking powder and ½ teaspoon salt.