Preheat oven to 325. Grease 3 baking pans with flour and butter.
Place sugar and flour into large mixing bowl.
In a sauce pan mix butter, cocoa, and water. Bring to a boil. Remove from heat and pour into the sugar and flour mixture. Stir well, then add buttermilk, soda, eggs, and vanilla. Mix til smooth.
Divide batter into three 6 inch baking pans. This can also be poured into a greased cookie cookie sheet if a more brownie type cake is desired. Bake for 325 for 26-28 minutes, or until cake springs back when touched.
Cream butter until light and fluffy
Add in cream, vanilla, and cinnamon.
Add in sifted powdered sugar 1 cup at a time until desired consistency. Press out air bubbles with a rubber spatula
Mexican Chocolate Ganache
In a microwave safe bowl add in chocolate chips, cinnamon, and heavy cream. Microwave for 30 seconds. Whish until smooth consistency. Add to squeeze bottle for cake drip.
On a cake turntable, tape a 6 inch cardboard round to the top of an 8-inch cardboard round. Top with a small amount of buttercream to use for glue.
Place first cake layer and Pipe a buttercream dam around outside of cake. Spread Mexican chocolate ganash inside the buttercream dam. Spread flat with an offset spatula. Add on next layer of cake and repeat with next layer.
Crumb coat the cake, place in fridge to set for about 5 minutes.