The 'long a' /eɪ/ is a 2-sound vowel. It is the middle sound in the word 'cake' /keɪk/.
To pronounce the sound, begin with the tongue pushed somewhat forward but in a neutral position in the mouth. Then, as the jaw closes slightly, move the body of the tongue upward until it is near the tooth ridge--similar to the position of a 'y sound' /y/. The front sides of the tongue touch the inside of the top teeth at the end of the sound.
Reference: https://pronuncian.com/pronounce-long-a