In a medium bowl, whip cream to soft peaks with a mixer. With the tip of a knife or a spoon, scrape vanilla seeds from pod and add to cream. Add condensed milk, whole milk, cardamom, pepper, and food coloring, if using, and beat cream 1 minute to rethicken a little. Stir in 1/3 cup pistachios by hand.
Divide mix among 8 (1/4 cup) popsicle molds*. Freeze until slushy, about 1 hour; then insert sticks and freeze until solid, about 5 hours more.
To unmold popsicles, either let sit at room temperature 5 minutes or run molds under warm water 10 to 15 seconds. Dip tops in remaining pistachios.
*Find natural food coloring online or at most Whole Foods markets. We used 3-oz. Dixie cups for these pops.
Make ahead: Up to 2 weeks, frozen.