Forget poppin' bottles at the club -- Daytona 500 winner Austin Cindric celebrated the biggest night of his career with burgers and milkshakes ... telling TMZ Sports he partied it up at a Steak 'n Shake!!
We spoke with the 23-year-old fresh off Sunday's victory in Florida ... and he told us he went to the famous burger spot with his whole crew to fuel up after the race.
"We took everybody -- including the Harley J. Earl trophy -- and we went to Steak 'n Shake," Cindric told us. "We closed the place down after midnight, and they stayed open for us, and we killed a bunch of burgers and milkshakes.