Sift together flour, corn starch, baking powder, and salt. In another bowl, add the sugar and butter together until soft, creamy and light. Beat in the 4 egg yolks, one at a time. Add vanilla and coconut milk.
Mix the liquid and the dry ingredients together, stirring the batter until smooth. Add coconut and lemon rind.
Whip the egg whites until stiff, but not dry, and fold them lightly into the batter.
Bake in greased or papered muffin tins for 350 18-22 minutes or until lightly browned. Check with a toothpick to be sure it comes out clean and is done. Allow the cupcakes to cool for a minute or two in the pan, then transfer to a wire rack to cool completely.
Cool and frost with Coconut Cream Cheese Frosting
* You can also use half vanilla extract and half almond extract.