Preheat oven to 375 degrees F (190 degrees C). Grease 10 X 15 inch jelly roll pan. Place a 22 inch length of waxed paper lengthwise in pan. Smooth paper so it conforms to pan, allowing excess to hang over ends of pan. Butter the waxed paper.
In a medium bowl, combine flour, baking powder and salt, set aside.
In a large mixing bowl, beat butter, sugar and vanilla until light and fluffy. Add eggs one at a time, beating well after each addition.
Stir in flour mixture 1/2 cup at a time, blending well after each addition. Stir in chopped nuts. Spread evenly in prepared pan.
Bake 10 - 15 minutes, or just until a toothpick inserted in the center comes out clean. Holding ends of waxed paper, lift cookie base out of pan and place on rack. Cool.
To prepare Glaze: In a large bowl, whisk together powered sugar and cocoa until no lumps remain. Add vanilla and 4 tablespoons milk. Add enough of the remaining milk to make a smooth, creamy glaze of medium consistency.
Line a large baking sheet with waxed paper. Place coconut on a large plate. Cut cookie base in 48 (1 1/4 X 2 1/2 inch) strips.
Use a fork to spear cookie rectangles; dip into chocolate glaze, allowing excess to drip back into bowl. Place chocolate dipped cookie on plate of coconut; use 2 forks to turn cookie so that all sides are coated. Place on prepared baking sheet and refrigerate until glaze is set. Store in airtight container at room temperature one week; freeze for longer storage.