Preheat oven to 350°F. Spray a 7-inch pre-form pan with removable bottom. Line the bottom of the pan with parchment paper and spray the paper. Melt semisweet and bittersweet chocolate with the butter in a heavy saucepan over medium low heat. Stir until chocolate and butter are melted and smooth. Add the sugar and salt and reduce heat to low. Stir pretty consistently until the sugar dissolves. This should take about 1 minute. Remove pan from heat. Whisk in eggs, one at a time. Beat vigorously when you put in each egg so that they do not cook. The mixture will look smooth and glossy when done. Add in the cocoa and mix until fully incorporated. Pour the batter into prepared pan and bake in preheated oven for about 20 minutes. The center of the cake should be just firm to the touch. Do not over bake. Cool in the pan for 15 minutes. Invert the cake on a cake tray. To prepare the glaze, melt the bittersweet and semisweet chocolate with the unsalted butter in a saucepan. You can use the same pan you used to make the cake if you wish. When melted and smooth, remove the pan from heat. Add the milk, agave syrup and vanilla and stir until smooth and glossy. Let the glaze cool for about 3 minutes before pouring it on the cake. Pour all of the glaze in the middle of the cake. Use a cake spreader to spread the glaze evenly over the cake, creating an even layer of glaze. If there is extra glaze, it might run down the sides of the cake. Chill the glaze in the fridge. Place the raspberries around the outside edge of the cake and one in the center. Cut and serve with the raspberry sauce. Serve and Enjoy!