Adjust oven rack to upper-middle position and preheat the oven to 450 degrees; line a jelly-roll pan or rimmed cookie sheet with foil. Reserve 3 cups of the tomato juices from the cans and remove visible seeds from the tomatoes. 

Spread the tomatoes in single layer on the foil lined pan, and sprinkle evenly with the brown sugar. Bake the tomatoes in the preheated oven until all liquid has evaporated and tomatoes begin to color – about 30 minutes. Allow the tomatoes to cool slightly, then peel them off the foil; transfer the tomatoes to a small bowl and set aside. 

In a medium-size, nonreactive saucepan, heat the butter over medium heat until foaming; add the shallots, tomato paste, and allspice. Reduce the heat to low, cover, and cook – stirring occasionally – until the shallots are softened – 7 to 10 minutes. 

Add the flour and cook – stirring constantly – until thoroughly combined – about 30 seconds. Whisking constantly, gradually add the chicken stock; then stir in the reserved tomato juice and the roasted tomatoes. 

Cover the saucepan, increase the heat to medium, and bring the mixture to boil; then, reduce the heat to low and simmer – stirring occasionally – to blend flavors – about 10 minutes. 

Strain the mixture into a medium-size bowl. Rinse out the saucepan. Transfer the strained tomatoes and solids from the strainer into a blender. Add 1 cup of the strained liquid to the blender, and puree until smooth. Add the remaining reserved liquid. 

Return the pureed mixture to the saucepan, add the cream, and heat over low heat just until hot – about 3 minutes. Off the heat, stir in the brandy or sherry; season to taste with salt and cayenne, and serve immediately. 

TO MAKE AHEAD: 
This soup can be prepared through the blender process, then, cooled, covered, and refrigerated for up to 3 days – or frozen for up to 2 months. Reheat over low heat before proceeding by adding cream, brandy or sherry and final seasonings.