Preheat the oven to 375F. Spray or lightly grease an 8 inch round cake pan or springform pan.
Combine butter and chocolate in saucepan and melt over low heat, stirring often. Pour mixture into a mixing bowl.
Add in sugar, salt and vanilla, mixing well. Next add in eggs and beat well to a smooth consistency and then fold in the cocoa powder.
Pour the batter into the prepared cake pan, scraping the bowl to get all the batter.
Bake for 25 minutes or until a instant-read thermometer inserted into the middle of the cake reads 200F.
Let the cake cool in the pan for 10-20 minutes and then loosen and tip out onto a cake plate to finish cooling.
To make the glaze, melt chocolate together with heavy whipping cream in a saucepan on low heat. Stir until chocolate ganache is smooth. Set aside and allow the chocolate ganache to come to room temperature, and/or thicken to the desired consistency for pouring over the cake. You don't want it to pour over the sides, which it will do if it is too thin.
Add a mixture of berries and slivered almonds to the top of the cake.