Directions

• Combine cocoa, 2/3 cup sugar, sifted cornstarch, salt, and espresso powder in a bowl. Set aside.
• In a medium saucepan, heat the cream on medium-low until just steaming.
• Stir in the cocoa mixture and continue stirring until sugar is dissolved, about 3 minutes.
• Add milk and stout to the cocoa/cream mixture. Increase heat to medium. Cook until good and hot.
• While liquid is heating, in a medium bowl, whisk together the egg yolks, the remaining tablespoon sugar, and vanilla. Place a damp paper towel under your egg yolk bowl so it doesn't slip around the counter as you whisk.
• When cocoa/cream mixture is hot, take about a cupful and drizzle it into the egg mixture while whisking the eggs like mad. This is called tempering the eggs, so you don't end up with scrambled eggs, which would be yucky in your pudding. Here's where the damp paper towel trick comes in handy.
• Pour the tempered egg mixture into the saucepan to join the pudding party. With the heat still at medium, stir continuously until really thick and pudding-y, about 10 minutes. Small bubbles are okay, but you don't want it to boil, so adjust the heat if necessary.
• Move the saucepan off the heat. Stir in the chocolate pieces until melted. Stir in the butter.
• Let cool and pour into small ramekins covered with plastic wrap, if desired. Chill for a few hours or serve slightly warm with whipped cream.