Fill a large bowl halfway with ice and water and set aside. Combine 1 1/2 cups cream, 1 1/2 cup milk, 1 cup sugar, 2 sticks canela, and 1/2 teaspoon salt in a large saucepan and bring to a simmer over medium heat. Simmer, stirring occasionally until sugar is dissolved, about 5 minutes.
Whisk 4 egg yolks vigorously in a large bowl until foamy and light in color, about 3 minutes. Remove cream mixture from heat and slowly pour about 1 cup into the yolks, whisking constantly.
Pour cream-egg mixture back into the saucepan and cook over medium heat stirring constantly, until custard coats the back of the spoon, about 5 minutes. Do not let it boil.
Remove custard from the heat and strain in to a large heatproof bowl. Remove canela from the strainer and return to custard. Place the bowl of custard into the bowl of ice water and chill 10-15 minutes, stirring occasionally.
Once the custard is cool, cover and place in the refrigerator overnight. Remove canela and freeze mixture in an ice cream maker according to the manufacturer's instructions. Most ice cream makers do not freeze the ice cream completely and it will need 4 to 6 hours in the freezer to harden, but best if left overnight.