Preheat oven to 350 degrees F. Grease and/or line an 8 inch square pan.
In a medium bowl, add the flour, ground pistachios, arrowroot starch, baking powder, baking soda, and salt. Whisk until well combined.
In a large bowl, add the olive oil, lemon zest, lemon juice, sugar, vanilla, almond milk, and applesauce. Whisk until well combined.
Add the dry to the wet. Use a spatula and mix until just combined. Don’t over mix. Pour batter into the prepared cake pan.
Bake for 25 minutes or until a toothpick inserted comes out clean. Let it cool for 10 minutes, then remove from the pan and place on a cooling rack to cool completely. Top with coconut whip and crushed pistachios if desired. You can also make a simple lemon glaze instead or do a dusting of powdered sugar on top. Enjoy!