Preheat oven to 350ºF with racks
in the lower and upper thirds. Combine butter and sugar
in a bowl. Using an electric mixer or wooden spoon, beat
until light and fluffy. Add lime oil; beat to combine. Gently
fold in lime zest, salt, flour, and coconut. Blend well.
Lightly flour hands and roll dough into small, approx. 1-in.
balls and place about 1-1/2 in. apart on an ungreased baking
sheet. Bake until puffy (not browned) and bottoms are just
golden, about 15 minutes. Allow cookies to cool on baking
sheets for about 5 minutes. Meanwhile, combine coating ingredients
in a quart- or gallon-size plastic bag. While cookies are
still warm, toss them in the coating. Remove and transfer
to wire rack to cool completely. Makes 4 to 5 dozen cookies.