Gourmet Magazine, January 1975, p.34
Semisweet chocolate squares
Fine granulated sugar
Hot strong coffee
Rum or brandy
In a large metal bowl set over a pan of hot water whisk together 4 egg yolks and 3 1/2 tablespoons fine granulated sugar with a large whisk until the mixture forms a ribbon when the whisk is lifted. Add 3 1/2 tablespoons sugar syrup, the hot chocolate mixture, and 1 1/2 cups hot strong coffee in a stream, whisking constantly, and stir in 1/2 cup rum or brandy. Divide the mixture among 4 glasses or cups.
In the top of a double boiler set over hot water melt 4 squares (4 ounces) semisweet chocolate. Add 1 1/2 cups scalded milk in a stream, stirring.