In a heavy-bottomed medium saucepan, whisk together egg yolks and maple syrup until well-combined. Whisk in cream and half and half, then set over medium heat. Whisking frequently, cook until a custard forms on the back of a spoon but a swiped finger leaves a clean line, 10 to 15 minutes. Stir in salt and strain into an airtight container. Chill overnight, or at least six hours.
The next day, churn in ice cream maker according to manufacturer's instructions. Return to airtight container and chill in freezer for at least three hours before serving.