Preheat oven to 250°F. Place pistachios in a single layer on a baking sheet, and toast until fragrant, about 10 minutes.
250 g pistachios
Pistachio cake:Turn oven temperature up to 350°F. Grease and line 3-8" cake tins with parchment paper. Grind pistachios into a powder (not a paste). Measure out 165g (1 1/2 cups) of ground pistachios. Set any remaining aside for garnish.
Sift together dry ingredients -- flour, baking powder, baking soda, salt and cinnamon -- then stir in the 165g (1 1/2 cups) of pistachios in a medium bowl.
300 g cake flour, 2 1/2 teaspoons baking powder, 1/2 teaspoon baking soda, 1 teaspoon salt, 1 teaspoon cinnamon
In the bowl of a stand mixer, mix together butter and sugar on high until mixture is light and fluffy, about 5-7 minutes, scraping down sides of bowl as necessary.
113 g unsalted butter, 350 g granulated sugar
Add in oil and thoroughly mix for one minute. Add eggs in one at a time on low speed. Add vanilla and almond extracts and 2-3 drops of food coloring if using.
1/4 cup canola or vegetable oil, 3 eggs, 2 egg whites, 1 tablespoon vanilla extract, 2 teaspoons almond extract, green food coloring
Alternating dry-wet-dry-wet-dry ingredients, slowly add in 1/3 of the dry mixture. Once almost fully mixed, add 1/2 of the milk. Repeat until all flour and milk is nearly incorporated.
1 cup whole milk
With a rubber spatula, stir in sour cream and incorporate any remaining streaks of flour.
55 g sour cream
Divide between the cake tins, bake for 23-27 minutes until a toothpick comes out clean and cakes spring back to the touch.
Cinnamon Icing: In the bowl of a stand mixer, beat cream cheese and butter with paddle until softened, about 5 minutes, scraping down bowl as needed.
500 g cream cheese, 113 g unsalted butter
Slowly add confectioners' sugar, cinnamon, and salt.
480 g confectioners' sugar, 2 teaspoons cinnamon, 1 teaspoon salt
Add vanilla and milk depending on preferred thinness of icing.
2 teaspoons vanilla, 1 to 2 tablespoons milk
Assembly: Trim top of cakes if desired, spread icing evenly throughout each layer. Top with pistachios, blackberries, raspberries, white chocolate chips etc.