Amazing Chocolate Cheesecake

Name: Amazing Chocolate Cheesecake
Ingredients: 1 1/2 cup fine graham cracker or digestive biscuit crumbs; 1/4 cup melted butter, or as needed; 1/2 tsp cinnamon; 3 tbsp brown sugar; pinch salt; 1 1/2 lb cream cheese, at room temperature; 2 cup sugar; 3 x large eggs; 8 x fine bittersweet chocolate ,at least 70% cocoa solids.; 4 tbsp heavy cream; 1 cup sour cream; 4 tbsp liqueur of choice; 2 tsp vanilla extract; 1 1/2 cup sour cream; 3/4 cup confectioner’s sugar (or to taste); 2 tbsp liqueur