If you are making the lemon stuffed coconut macaroons prepare the macaroons according to that recipe post & you will reserve some of the lemon custard from this recipe to fill the cups (approx 3/4 cup)
First prepare your coconut cake layers by greasing & parchment lining 4-6" cake pans, then preheat the oven to 350°F
Place all of the cake ingredients except for the coconut into a food processor & process until smooth batter (about 20 seconds) If you do not have a food processor it is no problem to mix this entire recipe by hand in a large bowl with a whisk!
Add the coconut flakes last mix to combine
Pour batter evenly between the prepared cake pans & bake in a preheated oven at 350°F for 25-30 minutes or until a toothpick inserted into the center comes out clean.
Cool the cakes in the pans until you can safely flip them onto a cooling rack to cool to cold
Prepare the lemon custard by combining the sugar & the cornstarch together in a heavy bottom medium sauce pot add the lemon juice, lemon zest, water & plant milk & a pinch of turmeric for color if desired
Cook over medium high heat stirring constantly to avoid scorching the bottom
Once it comes to a full boil remove it from the heat pour into a clean bowl & let it cool in the refrigerator while you prepare the buttercream recipe
Place the vegan butter in a stand mixer bowl with the paddle attachment (or with an electric hand beater) Add the salt *if using & cream on medium to high speed for about 3 minutes.
Scrape the sides and bottom of the bowl to make sure it is evenly mixed then add the coconut extract
Stop mixer & add the sifted confectioners sugar all at once. Mix on low speed until incorporated then scrape the bottom and sides of the bowl & mix on high speed for 3 minutes.
Assemble the cake as shown in the video tutorial