Divide the eggs into yolks and whites. Put 2 egg yolks and the granulated sugar in a bowl. Use a stainless steel bowl, since it will be heated later.
Whisk the yolks and sugar together well until it turns pale and thick.
Add milk to the mixture little by little, whisking vigorously as you drizzle it in.
Heat the bowl over very low heat. Keep mixing it up from the bottom using a silicone spatula until it's slightly thickened. Be careful not to burn yourself. If you're afraid to heat the bowl, transfer the mixture to a small pan first.
When the mixture has thickened, take it off the heat and cool the bowl in ice water.
Add 2 to 3 drops of vanilla essence. You can use vanilla paste instead.
Take the cream filling out of the Oreo cookies, and crush up carefully into small pieces, trying not to produce too much fine crumb.
Whip 1 egg white (about 30 g) and the heavy cream in separate bowls. Whip the meringue until firm.
Pour the halfway-whipped cream to the cooled egg mixture, and combine well.
If you have an ice cream maker, pour in the mixture, and start mixing.
Add the Oreo cookie bits about 10 minutes in. Don't add crumbs.
Add the meringue. Continue churning the ice cream following the machine instructions.
Transfer the finished ice cream to the freezer, and leave to rest overnight.
If you don't have an ice cream maker, put the mixture in a plastic freezer storage container and freeze.
Take it out every 40 to 50 minutes and mix it up thoroughly to incorporate plenty of air. Smooth out the surface and return to the freezer.
Add the meringue the 1st or 2nd time you mix up the ice cream. Repeat the mix-and-freeze procedure 4 to 5 times.
Add the Oreo cookie bits when you add the meringue. Mix well and freeze.
If you forget to mix the ice cream up according to schedule, it will form ice crystals and lose its creamy texture, so be diligent.
The ice cream is rested overnight in order to let the Oreo cookie bits become soft and moist.
Story Behind this Recipe
I make ice cream almost every day during the summer, and even in winter I make it about twice a week. I've used many recipes as the based and adapted them. If you crush the Oreos in a plastic bag and mix them in from the start to the ice cream mix, the crumbs will make the ice cream look dirty.
Break up the Oreo cookies so they don't turn into crumbs. Mix them in halfway through the churning process for a nice finish. The ice cream has to be rested however, or the cookie bits won't be softened enough. If you add the Oreo cookies at the start, the ice cream won't look as nice, but it will taste great.