Prepare the Rhubarb Compote: Combine chopped rhubarb, 1/2 cup sugar, and water in a small saucepan over medium heat. Bring to a simmer, stirring occasionally until the rhubarb breaks down and thickens slightly (about 10-12 minutes). Stir in 1 teaspoon of vanilla. Remove from heat and allow to cool completely in the refrigerator.

Prepare the Ice Cream Base: In a large bowl, whisk together the heavy cream, whole milk, 3/4 cup sugar, 1 teaspoon vanilla extract, and salt until the sugar is mostly dissolved and the mixture is well combined.

Chill the Base: Cover the ice cream base mixture and chill in the refrigerator for at least 2 hours, or preferably overnight, to ensure it is very cold before churning.

Churn the Ice Cream: Pour the chilled base into your ice cream maker bowl and churn according to the manufacturer's instructions, typically 20-25 minutes, until it reaches a soft-serve consistency.

Swirl in Rhubarb: During the last minute of churning, slowly drizzle in the cooled rhubarb compote. Stop the machine once it is lightly marbled throughout the ice cream.

Freeze to Harden: Transfer the swirled ice cream into a freezer-safe airtight container. Press a piece of plastic wrap directly onto the surface to prevent ice crystals, cover, and freeze for at least 4 hours before serving.