Preheat oven to 375. Line baking sheets with parchment paper or silpats.
In a large bowl, sift the flour with the sugar, baking powder, baking soda and salt. Add the lemon rind. Using two knives or a food processor, cut the butter into the flour mixture until the butter is evenly incorporated and there are no large chunks. Grate the almond paste and mix it into the flour mixture with ½ cup of the flaked coconut.
In a medium bowl, beat the coconut milk, egg and almond extract until well combined. Add the dry ingredients and beat with a spoon until the dough pulls away from the sides of the bowl and forms a ball. Knead 5 or 6 turns to get a nice consistency. The dough should be firm enough to roll out but still delicate, not stiff or dry.
On a lightly floured surface, roll out the dough to a 3/4 inch thickness. Either cut into triangles with a baking wedge or use a cookie cutter to cut shapes. Place on cookie sheets about 2 inches apart. Brush with the egg wash and sprinkle with the remaining ½ cup of coconut.
Bake for 18 minutes, or until they are a light golden brown and spring back to the touch.