Preheat the oven to 350 degrees. Spray the bottom of a 9-inch springform pan with cooking spray. Cut a piece of parchment or waxed paper in a circle to fit the bottom of the pan, put it in the pan and spray that with more cooking spray.

Melt butter and chocolate chips together in a microwave (about 2 minutes) or on top of a double boiler. Mix together the sugar, cocoa powder, crème de cassis, and salt. Add to the chocolate mixture, add the eggs and vanilla and mix well. Pour the batter into the prepared pan.

Bake for 45 minutes. Let cool in the pan for about 10 minutes or so, then finish cooling on a rack (or not, I often just let it cool in the pan).

Prepare the glaze by placing the 3 ounces of chocolate chips in a heat-proof bowl. Bring the cream just to a boil in a small pan over medium heat. Pour the cream over the chocolate chips, let sit for 5 minutes then stir until smooth and glossy. Stir in the crème de cassis and vanilla. Pour the glaze over the cooled cake.

Whip the cream with the powdered sugar until soft peaks form. Top the cake with the whipped cream and berries.