Gently heat the evaporated milk and sugar in a saucepan over medium heat, stirring until the sugar is dissolved.

Do not boil the milk mixture.

Remove from heat and let cool completely.

Cover the cooled milk mixture with plastic film and refrigerate for at least 1 hour.

Peel and pit the avocados.

Place the cooled milk mixture, avocado, chilled whipping cream, lemon juice, and vanilla extract in a blender.

Blend until smooth and creamy.

If using an ice cream maker, transfer the mixture to the ice cream maker and churn according to the manufacturer's instructions until firm.

Transfer the ice cream to a freezer-safe container.

If not using an ice cream maker, transfer the mixture to a metal container and place in the freezer.

Stir the mixture every 30 minutes until smooth and creamy.

Freeze for at least 1 hour before serving.

If frozen for more than 1 day, let sit at room temperature for a few minutes before serving to soften.