"I'm a believer," Cramer said on "Squawk on the Street," while emphasizing the speed with which Tesla built its Gigafactory 3 factory in Shanghai.
The plant, which is the company's first outside the U.S., was built in less than a year and Model 3 cars manufactured there were delivered to Chinese consumers Tuesday.
"Ten months he built that plant," the "Mad Money" host said emphatically.
Tesla manufactures more than 1,000 Model 3 vehicles weekly at its Shanghai factory, with intentions to grow production to near 3,000 per week, according to a report in the Global Times.
Shares of Tesla rose to almost 2% on Tuesday to notch an all-time intraday high of $462.06.
Cramer has not been shy in the past about speaking out on Musk and Tesla. He has both praised Musk by calling him a modern day "P.T. Barnum" and criticized Musk for incidents such as his "funding secured" tweet about taking Tesla private.
But in late November, Cramer began to turn more positive toward the company, due largely to the wishes of his wife, Lisa, who wanted a Model X sport utility vehicle.
"I give up. The car is too damn great," Cramer said then, while adding, "I have to admit it's just an unbelievable experience."
In December, Cramer declared he had gone from an "agnostic skeptic" to an "outright bull" on Tesla's stock, which is among the most polarizing on Wall Street.
Shares of Tesla have risen more than 100% since Sept. 24, when the stock traded at $223, and even what may have been considered a stumble for the company over that period appears to be of little consequence.
In November, Musk revealed the company's first electric pickup with much fanfare — and a little embarrassment.
The Telsa CEO said the truck was "bulletproof" against a 9mm handgun, except when he had the automaker's chief designer throw a metal ball at two windows, the "armor" glass smashed not once but twice.
Yet pre-orders of the Tesla's Cybertruck reached more than 250,000 in the week after it was debuted, Musk suggested on Twitter.
"The moment you throw a rock at a window and it goes right through it and the deposits soar, I mean c'mon," Cramer said.
Tesla's market cap was nearly $83 billion on Tuesday, compared to almost $36.5 billion for Ford and over $50 billion for GM.