Preheat oven to 375F.
Beat butter, granulated sugar, light brown sugar, eggs and vanilla in large bowl with electric mixer until creamy.
Beat in flour, baking powder, salt and baking soda just until blended.
Chill cookie dough in the refrigerator for about 1 hour. Chilled dough will help to keep the cookies from spreading too much when baking.
Drop 24 cookies (1 Tablespoonful each) onto baking sheets and bake 10-12 minutes or until edges are set. Cool 2 minutes on wire rack. Remove from sheets and cool completely on wire rack. Return remaining dough to the refrigerator.
Drop 24 cookies (2 teaspoonfuls each) onto baking sheets and bake 8-10 minutes or until edges are set. Cool 2 minutes on wire rack. Remove from sheets and cool completely on wire rack. Return remaining dough to the refrigerator.
Drop 24 cookies (1 teaspoonful each) onto baking sheets and bake 6-8 minutes or until edges are set. Cool 2 minutes on wire rack. Remove from sheets and cool completely on wire rack.
For each cookie tree: Glaze 1 large cookie, sprinkle with holiday sprinkles and place on flat surface, glazed side up. Repeat with another large cookie, 2 medium cookies and then 2 small cookies. Top with decorative candy.