In a saucepan, add the milk, whipping cream, vanilla, and the egg yolks. Beat with a whisk to mix everything together. Add the sugar and corn starch. and mix again, making sure to eliminate any lumps.
Turn on the heat to medium, and whisk continuously until the cream thickens. Once it starts to thicken, beat faster until the consistency is smooth and creamy.
Turn off the heat, and put the cream in in a shallow baking dish. Cover it with saran wrap (make sure the saran wrap makes contact with the cream - this will eliminate bubbles), and put it in the fridge until it cools.