1/2 vanilla bean, halved lengthwise
3 1/2 cups whole milk
1/2 cup turbinado sugar such as Sugar in the Raw
2 tablespoons cornstarch
1/2 pound bing cherries (1 1/2 cups; do not substitute frozen), pitted
2 tablespoons turbinado sugar
1 teaspoon pure almond extract
1 teaspoon pure vanilla extract
Scrape seeds from vanilla bean with tip of a paring knife into a small heavy saucepan. Add milk and a pinch of salt and bring just to a boil, then remove from heat.
Meanwhile, whisk together sugar and cornstarch, then add 1/2 cup hot milk, whisking until smooth. Whisk into milk in saucepan. Bring to a simmer, whisking, then simmer, whisking, 3 minutes. Immediately pour through a fine-mesh sieve into a metal bowl set in an ice bath. Cool to room temperature, stirring occasionally, about 10 minutes.
Remove from ice bath and chill, covered, 1 hour.
Pulse cherries, sugar, and extracts in a food processor until finely chopped, then chill, covered, 1 hour.
Make ice cream:
Stir cherries with their juices into gelato mixture and freeze in ice cream maker. Transfer to an airtight container and put in freezer to harden, at least 2 hours.