Here is the recipe:
3 cups GF flour - * see note below
2 tsp GF baking powder (made up beforehand from Thermomix EDC book)
3/4 tsp ground sea salt
3/4 cups sugar - use rapadura or raw
1/2 cup butter (made in TM)
2 tblsp lemon rind
3 eggs
1 1/4 cup buttermilk (made in TM)
1/2 cup oil - eg rice bran, grapeseed, or nut oil
Method:
Grind almonds to make almond meal and set aside in large bowl with the rest of the flour mix, baking powder and salt. Combine.
Place lemon rind and sugar in TM bowl and grind for 15 seconds on speed 10.
Add butter and cream on speed 5 until fluffy (about 10 seconds)
With blades turning on speed 4, add eggs 1 at a time until combined.
In a separate bowl, combine buttermilk and oil.
With blades turning on speed 4, alternately add the buttermilk mixture and the flour mixture until combined. Pour into a greased 20cm springform tin and bake for 40 minutes at 180C or until cooked.
* I make up a batches of GF plain flour using 2 cups rice flour, 2/3 cup potato starch and 1/3 cup tapioca flour and leave in the cupboard to use in place of plain flour. For this recipe I used 2 cups of this mix and 1 cup of almond meal to give more depth to the flavour and moisture to the cake (and better nutritionally)