For the filling, toss the raspberries with the sugar and crème de cassis in a bowl.
For the cake, coat a 9-inch round cake pan with butter and dust lightly with flour. Line the bottom with waxed paper. Butter and flour the waxed paper, shaking to remove the excess. Combine the chocolate, espresso powder and crème de cassis in a heavy saucepan. Cook over low heat until the chocolate melts, stirring frequently. Remove from heat. Cool slightly. Add the egg yolks one at a time, mixing well after each addition. Return saucepan to he heat. Cook for two minutes, stirring constantly. Remove from heat. Add the butter 1 tablespoon at a time, mixing after each addition until the butter melts. Stir in the flour. Beat the egg whites and salt in a mixing bowl until soft peaks form. Add the sugar gradually, beating constantly for 30 seconds or until glossy. Fold the egg whites 1/3 at a time into the chocolate mixture. Spoon the batter into the prepared pan. Bake at 375 degrees for 20 minutes or until the cake is slightly puffed but not completely cooked in the center. Cool in the pan on a wire rack for 45 minutes.
For the glaze, combine the chocolate, crème de cassis, water and espresso powder in a heavy saucepan. Cook over low heat until blended and of a glaze consistency, stirring frequently.
To assemble, invert the cake onto a cake plate; turn the cake right side up. Scoop out the top ½ inch of the cake, leaving a 1-inch border around the edge. Fill with the filling and pat lightly. Drizzle the cake with the warm glaze and spread to cover the top and side.