Root Beer Float with sprinkles

1 (18 1/4 ounce) package white cake mix 1 1/4 cups root beer 1/4 cup vegetable oil 2 large eggs 2 teaspoons vanilla extract 1 (16 ounce) can vanilla frosting[...]

1 cup packed brown sugar 1/2 cup butter or 1/2 cup margarine , softened 2 cups all-purpose flour 1/3 cup finely crushed root beer flavored hard candies (about[...]