Beat butter and shortening together with an electric mixer in a large bowl until light and fluffy. The mixture should be noticeably lighter in color.
Beat the vanilla extract into the butter mixture. Add sugar, one cup at a time, beating on medium speed until fully incorporated.
Add milk, one tablespoon at a time, beating on high until fully incorporated and you have frosting.
Dye your frosting with yellow food coloring until you reach the desired color. Save a small amount and dye that a bright orange.
Cupcakes
Prepare Cupcakes according to box cake mix instructions
Frost entire cupcake with yellow frosting, and dip into yellow sugar sprinkles. Add chocolate chips to make the eyes. You can also add a dab of white frosting to make the eyeball detail.
Using a rosette-frosting tip make “chick wings” on the sides and then sprinkle a small amount of the yellow sugar sprinkles on top. Then use a small amount of your orange frosting to make a beak and feet for your chick.