In a large bowl, cream butter and sugar until light and fluffy. Beat in the egg, cream and peel. Combine the flour, lemon drops, baking powder and salt; gradually add to the creamed mixture and mix well.
Drop by rounded teaspoonfuls 3 in. apart onto greased baking sheets. Bake at 350° for 8-10 minutes or until edges are lightly browned. Cool for 2 minutes before removing to wire racks.