In a cup, whisk together the egg yolks, sugar, and cornstarch and set aside.

In a small saucepan, place the milk, mashed bananas and butter. Bring to a simmer over medium heat for 10 minutes.

Let it cool for a few minutes. Slowly combine the milk with the egg mixture while whisking continuously.

Simmer for about 4-5 minutes while whisking frequently. Press the banana pulp gently through a fine-mesh to strain all the custard.

Return the custard to the saucepan, add vanilla and cook for 4-5 minutes or longer for smooth and thick custard

Serve and enjoy!