Toast the black sesame seeds for 15-20 seconds until they smell toasty. Use a spice grinder to turn your black sesame seeds into powder. Set aside.
Add the egg yolks and sugar into a bowl. Whisk until a smooth consistency and the egg mixture becomes a lighter yellow (~1 minute). Set aside.
Add whole milk, heavy cream and vanilla extract to a medium pan. Heat cream until hot and smoke is being emitted from the cream. Turn off the heat.
Add 1/4 cup of the hot cream to the eggs and whisk until it turns a smooth and uniform yellow color. The goal of this step is to raise the temperature of the eggs, so they don’t completely cook in the hot cream. Pour the eggs into the pan with the hot cream.
Turn the heat back on and heat the cream over low heat until it reaches 170 degrees F. A good way to test if it’s done is to coat the back of a spoon with the cream and pull your finger through the cream. A done cream should have a smooth, thick trail that doesn’t break. Take the cream off the heat. Strain the cream into a large bowl.
Add in your black sesame seed powder and mix well to incorporate. I would recommend using an immersion blender to incorporate.
Cool the cream down to room temperature and then put it in the fridge to cool completely. The cream should be in the fridge for about 20-30 minutes.
Pour the cream into an ice cream maker and churn for 15-20 minutes. The resulting ice cream should be slightly harder than soft serve.
Transfer the cream into a freezer safe container and freeze overnight before serving.