Chocolate Pudding

This is from one of Christina's recipe books. I asked her for the recipe a while back and then had a hard time finding it, so posting it here so I know where to find it next time! It's a keeper!

2 1/2 c. fat free milk, divided
1/3 cup sugar
3 tbsp. cornstarch
1/4 tsp. salt
2 large egg yolks, lightly beaten
2 tsp. butter
1 tsp. vanilla extract
5 ounces semisweet chocolate, chopped

Place 2 cups milk in a medium, heavy saucepan; bring to a boil. Combine sugar, cornstarch, and salt in a large bowl, stirring well with a whisk. Combine 1/2 cup milk and egg yolks, stirring well with a whisk. Add egg yolk mixture to sugar mixture, stirring well.

Gradually add half of hot milk to egg yolk mixture, stirring constantly with a whisk. Return milk mixture to pan; bring to a boil. Reduce heat, and simmer 1 minute or until thick, stirring constantly. Remove from heat. Add butter, vanilla, and chocolate, stirring until melted.

Spoon pudding into a bowl. Place bowl in a large ice filled bowl 15 minutes or until pudding is cool, stirring occasionally. Cover surface of pudding with plastic wrap; chill.