Preheat oven to 275 degrees F. (That low temperature is correct.) Grease and flour two 9-inch cake pans. (I also put parchment paper in the bottom of pans and then grease again.)
Separate eggs whites from yolks, set aside whites in a medium bowl.
In a large bowl, add the butter, granulated sugar, 1 cup of the coconut milk, and the egg yolks. Using a hand mixer, on medium speed, beat just until fluffy and combined.
In a separate bowl, whisk together the dry ingredients. Slowly add dry ingredients into the wet, with mixer on low speed, alternating with the buttermilk/ coconut extract mixture.
In the bowl of egg whites, add a pinch of salt and beat on high speed until stiff peaks form. Fold the egg whites into the batter until just combined. Divide batter evenly among the two cake pans. Bake for 60 to 65 minutes, or until toothpick inserted in center comes out clean.
Allow the cakes to cool in pans for 10 minutes, then invert onto a wire rack. Poke holes all over top of cakes (making sure not to poke all the way through.) Drizzle the remaining 1/2 cup of coconut milk onto both cakes.
Let cakes cool completely before frosting. (After my cakes were cooled I wrapped them in saran wrap and then put them in the fridge overnight, so they would be easy to frost the next day.)