Preheat oven to 325°F and grease four 5-inch baking pans with non-stick spray. Grease the edges and set aside. Sift almond flour, arrowroot starch, baking soda and sea salt in a large bowl and set aside.
Separate the eggs from the egg whites and place the egg whites in a medium bowl. Place the yolks in a separate bowl with melted butter, maple syrup, vanilla, and lemon juice and whisk to combine. Add this mixture to the flour mixture and mix until smooth.
Beat the egg whites using a hand mixer until whipped and fluffy, about 2 minutes, then set aside to sit for a moment. Gently fold in the whipped egg whites into the batter about ⅓ cup at a time, mixing carefully.
Divide the batter between four 5-inch greased baking pans. Bake for 35-40 minutes, or until the toothpick comes out clean. Let the cakes cool on a wire rack for 10 minutes before turning the cakes onto the rack. Be very careful when doing this to prevent the cakes from falling apart.
Next, make the pistachio paste. place pistachios in the bowl of a food processor. Pulse until the nuts are in small bits. Add the cane sugar, almond extract and almond milk and blend until relatively smooth. Set aside.
To make the frosting, combine the cream cheese, pistachio paste, vanilla and maple syrup in the bowl of a stand mixer. Mix with a paddle attachment until smooth. Once the cakes have cooled off, carefully slice the cakes in half from the edges. Frost each layer of the cake, or frost however you would like!
Recipe by My Digital Kitchen at https://www.mydigitalkitchen.ca/2019/04/13/vanilla-pistachio-cream-cake/