Preheat oven to 350°F (175°C) and grease two 9-inch round cake pans.
Sift together cake flour, granulated sugar, baking powder, and salt in a large bowl.
Add softened butter and 0.75 cup of coconut milk, mixing on low speed until combined, then on medium for 2 minutes.
In a separate bowl, whisk egg whites with remaining 0.25 cup coconut milk, coconut extract, and vanilla extract.
Gradually fold the egg white mixture into the batter in three additions until smooth.
Divide batter evenly between pans and bake for 30-35 minutes until a toothpick comes out clean.
Cool cakes in pans for 10 minutes, then transfer to wire racks to cool completely.
Whip heavy cream and powdered sugar until stiff peaks form.
Frost the cooled cake layers and coat the exterior with toasted shredded coconut.