Prepare an ice bath by filling a large bowl with ice cubes and 1 to 2 cups of water. Place a medium bowl fitted with a fine strainer inside the ice bath.
In a medium saucepan, combine the milk, cream, 1/2 cup sugar, milk powder, salt and vanilla. Set over medium heat, stirring occasionally, until the mixture is warm and begins to steam, about 5 minutes.
In a medium bowl, whisk together the egg yolks and the remaining 1/4 cup sugar. Carefully whisk half of the warm milk mixture into the egg yolks, one ladleful at a time, until the egg mixture is warmed. Whisk the egg-milk mixture back into the saucepan. Cook the mixture over medium heat, stirring constantly with a wooden spoon, until the mixture is thick enough to coat the back of the spoon and registers around 175 degrees F on an instant-read thermometer, about 5 to 7 minutes. Be careful not to boil the mixture.
Immediately strain the mixture through the fine strainer into the prepared ice bath. Cool the custard in the ice bath until it reaches room temperature, stirring often. Press plastic wrap against the surface of the custard and refrigerate until chilled, about 4 hours or up to 1 day.
Pour the chilled mixture into an ice cream maker and freeze according to the manufacture's directions. Transfer the ice cream to an airtight container, press plastic wrap against the surface of the ice cream, and freeze until firm and the flavor is ripened, at least 2 hours.