Tried 16oz half/half with a little milk, 1 packet gelatin, 1.5 caps vanilla, 3oz brown sugar.
A little too solid, sweet. Cut back on vanilla to 1 cap. Color is unattractive, but tasty. Cut sugar to 2oz.
https://www.davidlebovitz.com/perfect-panna-cotta/
4 cups (1l) heavy cream or half-and-half
1/2 cup (100g) sugar
2 teaspoons of vanilla extract, or 1 vanilla bean, split lengthwise
4 teaspoons powdered unflavored gelatin (slightly less than 2 packets)
6 tablespoons (90ml) cold water
http://www.seriouseats.com/recipes/2017/08/classic-panna-cotta-vanilla-bean-recipe.html (Stella Parks)
14 ounces heavy cream (about 1 3/4 cups; 395g)
8 ounces whole milk (about 1 cup; 225g)
1 Tahitian vanilla bean, split lengthwise, seeds reserved (see note)
2 1/2 ounces sugar (about 1/3 cup; 70g)
1/2 teaspoon (2g) Diamond Crystal kosher salt; for table salt, use about half as much by volume or use the same weight
For the Gelatin:
1/4 ounce unflavored gelatin powder (about 2 1/8 teaspoons, though volume may vary by brand; 7g), such as NOW Foods (see note)
2 ounces whole milk (about 1/4 cup; 55g)
1/2 teaspoon vanilla extract
Gelatin needs to bloom in cold milk for 10 minutes.
Giada De Laurentiis
1 cup whole milk
1 tablespoon unflavored powdered gelatin
3 cups whipping cream
1/3 cup honey
1 tablespoon sugar
Pinch salt
2 cups assorted fresh berries