Preheat oven to 350F (175C). Grease and flour a 9x13 inch baking pan.
In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
In a large bowl, cream together butter and sugar until light and fluffy. Beat in eggs one at a time, then stir in vanilla extract.
In a small bowl, combine buttermilk and coconut milk.
Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk mixture, beginning and ending with the dry ingredients. Beat until just combined.
Stir in 1 cup of the shredded coconut.
Pour batter into the prepared pan and spread evenly.
Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
Let cool in the pan for 10 minutes before inverting onto a wire rack to cool completely.
Frosting Instructions
In a large bowl, cream together softened butter and powdered sugar until smooth.
Gradually add coconut milk and vanilla extract, beating until light and fluffy.
Frost the cooled cake with the coconut frosting.
Sprinkle the remaining 1/2 cup shredded coconut over the frosted cake.
Cut, serve, and enjoy!
Tips:
For a more intense coconut flavor, toast the shredded coconut before adding it to the batter. Buttermilk can be substituted with 1 cup of milk mixed with 1 tablespoon of lemon juice or white vinegar, let stand for 5 minutes before using. If coconut milk isn't available, use regular milk, but the overall coconut flavor will be less pronounced.