Preheat oven to 350 degrees. Grease and flour a 9×13 baking pan.
In a large bowl, mix together the flour, sugar, buttermilk, butter, brown sugar, and eggs. Mix by hand; add the cocoa, cinnamon, baking soda, baking powder, and salt.
Mix well and spread into the greased 9×13 pan.
In a separate bowl, mix the dry topping ingredients (brown sugar, almonds, chocolate chips) and sprinkle over the batter.
Refrigerate overnight (or follow the steps of adding butter and baking, if you plan to serve right away).
In the morning, preheat oven to 350 degrees. Drizzle the cake with melted butter.
Place the pan in the oven and bake for 35 minutes until the top is rich golden brown. Cool for 15 minutes. Cut into squares and serve!