Chill the can of coconut milk upright overnight and scoop out only the firm cream for the frosting - the watery liquid left behind will not whip. Note that the coconut milk, coconut yogurt, coconut oil, vanilla, almonds, sugar, and lemon zest are all for the frosting, not the batter. Store the frosted cake in an airtight container in the fridge for up to 3 days.