Broken into small pieces Or semisweet chocolate bits) Heat oven to 180ºC . Mix crumbs and butter and press onto bottom of 23 cm springform pan. Bake for 10 minutes. Beat cream cheese, sugar, and vanilla until well blended. Add eggs, one at a time, mixing well after each addition. Blend in melted chocolate and pour over crust. Bake 40 minutes, turn off oven and let cake cool inside the oven as it cools down. Loosen cake from rim of pan and cool completely. Chill for at least 4 hours. Remove rim. Heat heavy cream, butter, and sugar in a heavy saucepan over medium-high heat. Stir to dissolve sugar crystals and then bring to a boil. Put chocolate pieces into a stainless steel bowl and pour boiling cream mixture over it and let stand for a few minutes. Stir until smooth and cool. Cover the sides and top of cheesecake with the ganache, smooth, and chill at least 2 hours to set. ----