In large bowl, beat 250 g cream cheese, 1/2 cup softened butter and pumpkin with electric mixer on medium speed about 1 minute or until well blended; scrape side of bowl.
Beat in egg until smooth.
On low speed, beat in cake mix and 1 tablespoon pumpkin pie spice until blended.
Drop dough by rounded tablespoonfuls 2 inches apart on ungreased baking sheets.
Bake 13 to 15 minutes or until edges are light golden brown.
Cool on baking sheet 2 minutes; remove from baking sheet to cooling rack.
Cool completely, about 20 minutes.
In medium bowl, beat Frosting ingredients with spoon until smooth.
Spread about 2 teaspoons frosting on each cookie.
Sprinkle 1/2 teaspoon pumpkin pie spice on tops of frosted cookies.