Preheat oven to 375 degrees and grease a 9" circular cake pan or an 8x8 square baking pan.
In a small bowl, mix together flour, cocoa powder, sugar, baking soda, baking powder, cinnamon, espresso powder and salt.
In a separate mixing bowl, lightly mix together oil, egg, vanilla, creamer, sour cream, and milk.
Make a well in the center of dry ingredients, and pour wet ingredients into it. Stir gently, as to not over stir the mix.
Once just combined, fold in dark chocolate chips. Pour into your pan and set aside.
In a small bowl, mix together the topping ingredients until combined. Sprinkle evenly over the top of the batter in the pan. Use a rubber spatula to swirl the topping.
Bake for 25 minutes or until your cake tester comes out clean.
While the cake is cooling, make the icing by stirring together the powdered sugar and milk. Drizzle over the top of the coffee cake.
Serve warm, or cool.
Enjoy!