Preheat oven to 350°. In a large bowl, beat butter and sugar until blended. Beat in eggs and vanilla. In a small bowl, whisk flour, cocoa, baking powder, baking soda and salt; gradually beat into sugar mixture. Shape dough into 1-1/2-in. balls. Place 3 in. apart on greased baking sheets.
Insert a lollipop stick into each cookie. Flatten with a glass dipped in sugar. Bake 10-12 minutes or until cookies are set. Remove from pans to wire racks to cool completely. Tint frosting; frost cookies. Decorate with gel and optional decorations as desired.