In a large saucepan, mix the milk, cream, ¾ cup of the sugar, salt, and corn syrup together on medium heat.
Bring the saucepan to a boil for about 1 - 2 minutes, then lower to a simmer. Stir and scrape the sides and bottom of the saucepan frequently to prevent burning.
In a small bowl, mix the egg yolks, ¼ cup (50 g) of sugar and the cornstarch until well-combined.
Slowly add 1 cup (250 mL) of the hot milk mixture to the eggs while whisking the yolks. Whisk the eggs back into the saucepan.
Mix the contents of the saucepan constantly until it forms a thick custard.
Test this by dipping a wooden spoon in the mixture, then running your finger down the back of the spoon. If a line where you swipe remains there, the custard is ready. It should take about 5 minutes.
Prepare an ice bath - it should be more ice than water. Fill a large freezer bag with the custard and let it rest in the ice bath for about 30 minutes.
Chill the custard in the refrigerator until completely cool.
Put the cooled custard and the vanilla in your ice cream maker and prepare according to manufacturer instructions.
Transfer the ice cream to an airtight container and free until solid about 4 hours.
Notes
*If you do not have an ice cream maker, place the ice cream in a container and place in the freezer. Every 30 minutes for about 3 - 4 hours, mix the ice cream. Be sure to scrape the sides and bottoms to break up the ice crystals. Use am immersion blender if you have one available.