Bring the cream to a gentle boil in a medium saucepan. Remove from the heat.
In a small mixing bowl, whisk together the egg yolks and sugar until slightly thickened and lemon-colored. Whisk 1/2 cup of the hot cream into the egg mixture. Whisk in the coffee powder, and cinnamon. In a slow, steady stream, gradually add the egg mixture to the pan of hot cream. Cook over medium-low heat, stirring occasionally, until the mixture thickens enough to coat the back of a spoon and reaches 170 degrees F on an instant-read thermometer, 2 to 3 minutes.
Remove from the heat and strain into a clean bowl through a fine mesh strainer, pressing against the strainer with the back of a spoon. Add the brandy and vanilla, and stir to blend. Serve immediately. (If not serving immediately, press plastic wrap on the surface of the custard to prevent a skin from forming and refrigerate.)
Yield: 3 cups