Bittersweet Chocolate Custard Ice Cream

1 cup half and half

3/4 cup sugar

1/2 cup cocoa powder

2 cups whipping cream

1 teaspoon vanilla

Place first four ingredients into blender. Cover and process on low until smooth. Pour into medium saucepan and cook over low heat, stirring constantly, until bubbles form around edge of mixture.

Chill and then pour into cream canister. Add whipping cream and vanilla, then freeze as directed.