The puddings, served with Espresso Creme Anglaise and topped with whipped cream, are intensely chocolatey but surprisingly light.
Preheat the oven to 325 degrees. Combine 6 tablespoons sugar with the flour, cocoa, and espresso powder in a large bowl; whisk to combine.
Melt chocolate and butter in a medium heat-proof bowl set over a pan of barely simmering water. Remove from heat; stir in scalded milk and vanilla. Whisk chocolate mixture into flour mixture until well combined.
Beat egg yolks until pale and very thick, 2 to 3 minutes. Gradually pour in chocolate mixture, whisking constantly.
Whisk egg whites until frothy. Add remaining 2 tablespoons sugar, and whisk until stiff peaks form. Whisk egg whites into chocolate mixture.
Place four 1-cup ramekins or oven-proof cups in a roasting pan, and fill each with batter. Pour boiling water into roasting pan so that it comes halfway up the sides of the baking cups. Bake 45 to 50 minutes, until the tops begin to crack. Remove roasting pan from the oven, and transfer the baking cups to a wire rack to cool slightly.
Just before serving, whip the heavy cream until soft peaks form. Serve the steamed puddings warm, topped with the espresso creme anglaise and whipped cream.
We found that when making these steamed puddings, whisking instead of folding the egg whites into the melted chocolate mixture produced the creamiest texture.