Preheat oven to 400 F. Grease a 9"x13" pan.
In a medium bowl, sift together flour, cocoa powder, cinnamon, baking powder, salt, and soda. Set aside.
In another bowl, beat together sugar and butter until well combined. Beat in eggs, one at a time, until thoroughly blended.
In a small bowl, whisk together the coffee and skyr. Add the dry ingredients and the skyr mixture to the butter mixture, alternately, beginning and ending with the dry ingredients. Beat on medium speed until blended, although a few small lumps may remain.
Pour batter into prepared pan and bake for 25 minutes, or until a wooden toothpick inserted into the center comes out clean. Cool completely.