In a large bowl whisk together the yolks and sugar till thick and pale yellow.
Add cream and vanilla, and whisk till blended well.
Strain into a large bowl and skim any bubbles or foam.
Place about 1 tablespoon of Mocha Espresso Sauce in each of 6 ramekins.
Add custard mixture to each of the ramekins and place in a water bath.
Bake till set around the edges but a little loose in the center, about 40 to 50 minutes. Remove from oven and cool in the water bath. Chill at least two hours.
To serve, sprinkle about two teaspoons of sugar on each ramekin. Use a small torch or your broiler to melt sugar. Re-chill for a few minutes before serving.