Preheat oven to 350°. Spray 13 x 9-inch baking dish with nonstick cooking spray.
In large bowl, with mixer on medium speed, beat pumpkin and eggs until well blended. Reduced speed to low; gradually add cake mix and beat just until blended. Evenly spread cake mixture in prepared dish. Bake 25 to 30 minutes or until toothpick inserted in center comes out clean. Cool completely on wire rack.
In large bowl, with mixer on low speed, beat cream cheese, butter and extract until smooth, scraping bowl occasionally with rubber spatula. Gradually add powdered sugar and beat until well blended.
Evenly spread cooled cake with frosting and top with sprinkles.