Preheat the oven to 400 degrees F.
Generously butter four 3/4-cup souffle dishes or custard cups. Arrange on a baking sheet.
Stir the chocolate and butter in heavy small saucepan over low heat until smooth. Remove from the heat; stir in the mescal. Cool 10 minutes, stirring occasionally.
Using an electric mixer, beat the eggs, yolks, 4 tablespoons sugar, molasses, 1 teaspoon canela powder and salt in medium bowl until very thick ribbons fall when beaters are lifted, about 6 minutes. Sift the flour over the batter; fold in the flour. Fold in the chocolate mixture. Divide the batter among the prepared dishes, filling completely. (Can be made 1 day ahead. Cover loosely; refrigerate. Let stand at room temperature 30 minutes before baking.)
Bake the cakes until the tops are puffed and dry and a tester inserted into the center comes out with moist batter still attached, about 15 minutes. Cool the cakes 5 minutes.
Beat the cream, the remaining 1 tablespoon sugar and the remaining 1/2 teaspoon canela powder in small bowl until firm peaks form. Top the cakes with the whipped cream and serve warm.