The spelling of "am top heap" is straightforward once you understand the pronunciation. In IPA phonetic transcription, it is written as /æm tɒp hiːp/. This means that the first sound is the short "a" sound, followed by the "m" sound. Then, the "t" is pronounced and followed by the "o" sound as in "hot". The next sound is the long "e" sound, and the final sound is the "p" sound. So, the spelling of "am top heap" is simply a reflection of its phonetic pronunciation.