STEP 5: To make the frosting, beat butter until light and creamy. Add powdered sugar and continue to beat until combined. Add the milk, one tablespoon at a time.
STEP 6: Leave one third white and use gel food coloring to tint the second portion yellow and the third portion orange. Pipe a swirl of yellow, followed by a swirl of orange on top, and a swirl of white on top of that.