Preheat your oven to 180° C. Prepare 2 22cm pans by buttering and lining the pans with baking paper.
Add the flour, ground pistachios, baking powder, baking soda, salt and cinnamon to a medium mixing well and whisk.
Add the butter to the bowl of a stand mixer and beat for about 2 minutes until creamy and soft. Add the sugar and beat some more until fluffy and light. Add the vanilla essence, almond essence and egg and mix well.
Alternate adding the flour, milk and buttermilk while mixing on a low speed. Do not overmix!
In a clean metal bowl that has been wiped down with vinegar add the 3 egg whites with the cream of tarter and beat untillstiff peaks form.
Divide the batter between the two pans and bake for 35 minutes. Do a skewer test to make sure the cake has finished baking.
Remove from the oven and let the cakes cool down completely before decorating.