The pralines make this a special gelato.
Combine 1/2 cup of the sugar with 2 tablespoons water in a heavy saucepan. Cook over low heat until sugar is dissolved. Cover pan and bring to a boil. Leave cover on until condensation washes down sides of pan. Turn heat to medium and cook, swirling pan occasionally, until sugar turns amber in color and registers 320 degrees on a candy thermometer. Remove pan from heat and very carefully pour in cream to stop the cooking process. Stir and let cool.
Bring milk to a simmer. Meanwhile, combine egg yolks and remaining sugar in the bowl of an electric mixer. Beat at medium-high speed until very thick and pale yellow, 3 to 5 minutes.
Add half the milk to egg-yolk mixture and whisk until blended. Stir into remaining milk and cook over low heat, stirring constantly, until mixture is thick enough to coat a spoon.
Remove from heat and stir in caramel-cream mixture. Pass mixture through a strainer into a medium bowl set over an ice bath to chill. Freeze in an ice-cream maker according to manufacturer's instructions. Add praline and mix in machine until combined, about 30 seconds. Store in a plastic container.
For best flavor, soften it slightly in the refrigerator before serving.