Add whole milk, heavy cream, and vanilla extract to a medium pan. Heat cream until warm. Pour cream into a small bowl with the lavender flowers. Steep for 30 minutes.
Add the egg yolks and sugar into a bowl. Whisk until a smooth consistency (~1 minute). Set aside.
Strain the cream back into the 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 hot cream.
Turn the heat back on and heat the cream 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 thick, smooth trail that doesn’t break. Take the cream off the heat.
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.
Spoon the ice cream into a freezer safe container and freeze overnight.