In a small bowl, combine the all-purpose flour, baking powder, and salt.
In a large mixing bowl, beat together the softened butter and granulated sugar until light and fluffy. Mix in egg and vanilla extract. Gradually add in the flour mixture.
Divide the dough into thirds and place in separate bowls. For each bowl, add one of the following mixtures: sweetened coconut, strawberry mix, and melted chocolate. Mix each well.
Line a 9"x5" loaf pan with parchment paper with ends extending over the sides. Press the strawberry dough onto the bottom of the pan. Cover with a coconut layer, and top with the chocolate dough. Gently press layers together to seal. Cover with plastic wrap and refrigerate for 3 hours until firm.
Preheat oven to 350 degrees. Remove dough from pan and discard parchment. Cut dough into 3 lengthwise strips, then cut each into 1/4" slices.
Place 1-inch apart on baking sheets covered with a silicone baking mat or parchment paper. Bake for 9-11 minutes until cookies are firm to the touch and just lightly browned on bottom. Cool on wire racks. Makes 90 small cookies.
Notes
*Unless otherwise indicated, all butter used on this recipe site is salted.