Cook the chocolate, whipping cream, sugar, cinnamon, almon extract and salt in a small saucepan over low heat, whisking occasionally, until mixture is smooth and chocolate is melted, about 3 to minutes.
Remove from heat and whisk in butter until melted.
Serve immediately.
Baking the cake
Preheat oven to 325°.
Microwave chocolate baking squares in a microwave-safe bowl at high until chocolate is melted and smooth, stirring at 15-second intervals.
Beat the butter at medium speed with a heavy-duty electric stand mixer until creamy, about 2 minutes.
Gradually add granulated sugar, beating until light and fluffy about 5 to 7 minutes.
Add eggs, 1 at a time, beating just until yellow disappears after each addition.
Stir in melted chocolate, chocolate syrup, and vanilla until smooth.
Combine the flour, ground cinnamon, baking soda and salt.
Add the dry ingredients to the butter mixture alternately with buttermilk, beginning and ending with flour mixture. Beat at low speed just until blended after each addition.
Pour batter into a greased and floured 10” (14-cup) tube pan.
Bake at 325° for 1 hour and 10 minutes or until a long wooden pick inserted in center of cake comes out clean.
Cool in pan on a wire rack 10 to 15 minutes; remove from pan to wire rack, and let cool completely.