1/2 cup butter, softened
1 cup packed light brown sugar
1 large egg
1 tsp vanilla extract
1 1/2 cups all-purpose flour
1/3 cup unsweetened baking cocoa
1/2 tsp baking soda
1 cup chopped pecans
1 cup flaked coconut
Cream the butter and brown sugar together in a large bowl until blended. Beat in the egg and vanilla extract.
Combine the flour, cocoa powder, baking soda, and pecans in a small bowl to blend together well. Add to the butter mixture, blending until a stiff dough forms. Sprinkle the coconut on a flat work surface.
Divide the dough into 4 parts. Shape each part into a roll about 1 1/2-inches in diameter; roll in the coconut until heavily coated. Wrap in plastic wrap and refrigerate until firm; at least one hour but up to 2 weeks. (May be frozen up to 6 weeks.)
Preheat oven to 350 degrees.
Line cookie sheets with parchment paper or just leave ungreased.
Cut dough into slices about 1/8-inch thick. Place slices 2-inches apart on the baking sheets. Bake at 350 degrees for 10 to 13 minutes or until firm. Do not overbake. Remove from pans and cool on wire racks.