1. Combine first 4 ingredients in a large bowl; beat until smooth and creamy.
2. Add orange rind and juice; beat well.
3. Combine flour, baking powder, soda, and salt; gradually add to creamed mixture, beating well.
4. Drop dough by teaspoonfuls onto greased cookie sheets; bake at 350 degrees for 14-16 minutes or until edges just begin to brown.
5. Cool on wire racks.
6. Spread tops of cookies with orange glaze.
7. Orange Glaze: Combine all ingredients; beat until smooth.