In a small pot, combine 2 cups of whole milk, ½ cup of granulated sugar, and ¼ cup of cornstarch. Whisk until smooth.

Place the pot over medium heat and stir gently but constantly for about 5-7 minutes until it thickens and bubbles gently.

In a separate bowl, whisk together 3 egg yolks until pale. Gradually mix in about ½ cup of the hot pudding mixture to temper the yolks.

Stir the tempered egg yolks back into the pot with the remaining pudding. Cook for an additional 1-2 minutes, stirring constantly.

Remove from heat and mix in 2 teaspoons of vanilla extract and 2 tablespoons of butter until fully combined.

Pour the pudding into serving bowls, cover with plastic wrap, and refrigerate for at least 2 hours.

Serve chilled with fresh berries or whipped cream.