Preheat the oven to 400 degrees F. Reserve 12 raspberries. Combine the remaining raspberries with the sugar and puree in a blender. Strain through a strainer and set aside. Brush some of the butter on a work surface. Arrange 1 of the phyllo sheets on top and brush with some of the remaining butter. Repeat the procedure with the remaining 2 sheets and butter and cut the phyllo into 12 (4-by-3/12-inch) squares.
Divide the chocolate evenly among the 12 squares, mounding it in the center of each and top with one of the reserved raspberries. Bring up the edges of the phyllo to enclose the filling and pinch at the top to form a little package or purse. Arrange the purses on an ungreased baking sheet and bake on the middle rack of the oven until golden, about 12 to 15 minutes.
To serve: spoon 2 tablespoons of the sauce in the middle of 4 dessert plates and swirl the sauce to spread it in a circle. Sprinkle the purses with confectioners' sugar. Arrange 3 purses and 1 small scoop of ice cream on each plate and garnish with the mint sprig.