Preheat the oven to 350°F and prepare an 8x4 or 9x5 loaf pan by lining it with parchment paper. Set it aside.
Combine the pistachio milk, vegetable oil, lemon juice, lemon zest, vanilla extract, almond extract, and a tiny drop of green food colouring in a large mixing bowl. Whisk these wet ingredients together until well combined.
Combine the flour, cornstarch, sugar, baking powder, baking soda, and salt in a separate large mixing bowl. Stir these dry ingredients together.
Add the dry mixture to the wet mixture and stir until just combined, being careful not to overmix. Stop mixing once you no longer see any dry flour patches.
Pour the batter into the prepared loaf pan.
Bake for 45-50 minutes or until a toothpick comes out clean. Allow the cake to cool in the pan for 30 minutes, then transfer it to a cooling rack. Let it cool completely before adding the icing.