For a traditional French dessert, top velvety custard with golden caramel, then spoon into cups.
Stir gelatin and 2 teaspoons water in a small bowl until dissolved.
Put 3/4 cup sugar into a large skillet over medium-high heat. Cook, without stirring, until sugar at edges begins to melt and turn clear, about 3 minutes. Continue to cook, stirring constantly, until medium amber, 1 1/2 to 2 minutes. Remove from heat. Stir in 1/2 cup plus 2 tablespoons water. If sugar begins to solidify, return pan to medium heat until melted. Set caramel aside to cool completely.
Prepare an ice-water bath; set aside. Whisk eggs and yolk in a medium bowl; set aside. Bring cream, milk, 1/4 cup sugar, and the salt to a simmer in a medium saucepan over medium-high heat. Whisk half the hot cream mixture into the eggs. Pour cream-egg mixture back into saucepan. Add gelatin mixture; whisk until combined. Reduce heat to low. Cook, stirring constantly, just until mixture is thick enough to coat the back of a spoon, about 3 1/2 minutes.
Pour custard into a bowl set in the ice-water bath. Let cool completely, stirring constantly, about 3 minutes. Transfer to a large, shallow bowl. Refrigerate until set, at least 30 minutes. Pour reserved caramel over custard. Divide among serving cups or bowls.