Prep: 45 min. + chilling Process: 10 min. + freezing
1-1/4 cups whole milk
12 fresh basil leaves
1 cinnamon stick (3 inches)
1/2 cup sugar
4 large egg yolks, lightly beaten
3/4 cup heavy whipping cream
1/4 teaspoon vanilla extract
In a small saucepan, heat milk to 175°. Remove from the heat; add basil and cinnamon stick. Cover and steep 30 minutes. Strain, discarding basil and cinnamon stick.
Return to the heat; stir in sugar until dissolved. Whisk a small amount of the hot mixture into egg yolks. Return all to the pan, whisking constantly. Cook and stir over low heat until mixture is just thick enough to coat a metal spoon and a thermometer reads at least 160°, stirring constantly. Do not allow to boil. Remove from heat immediately.
Quickly transfer to a large bowl; place bowl in a pan of ice water. Stir gently and occasionally for 2 minutes. Stir in cream and vanilla. Press plastic wrap onto surface of custard. Refrigerate several hours or overnight.
Fill cylinder of ice cream maker no more than two-thirds full; freeze according to manufacturer’s directions. (Refrigerate any remaining mixture until ready to freeze.)
Transfer ice cream to freezer containers, allowing headspace for expansion. Freeze until firm, 2-4 hours.