With the rack in the middle position, preheat the oven to 200 °C (400 °F). Lightly butter six 125 ml (1/2 cup) ramekins and sprinkle generously with sugar.
In a saucepan, off the heat, combine the sugar and flour. Add the milk and bring to a boil, stirring with a whisk. Simmer for about 1 minute. Remove from the heat and stir in the raspberry liqueur. Let cool.
With a whisk, stir the egg into the cooled custard. Set aside.
In a bowl, combine the frozen raspberries and jam. Divide among the ramekins. Set aside.
In a bowl, beat the egg whites and cream of tartar with an electric mixer until soft peaks form. Gradually add the sugar, beating until stiff peaks form.
With a whisk, stir about a quarter of the meringue into the pastry cream to lighten it. With a spatula, gently fold in the remaining meringue. Spoon into the ramekins (ideally up 1-cm / ½-inch to the edge) and smooth the top. Bake for 20 to 22 minutes or until the soufflés are fully risen and golden brown. Serve immediately.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.