Preheat oven to 350 degrees. Butter 9x5x3'' loaf pan and set aside.
In a small bowl combine 1/3 cup sugar and 1 tablespoon cinnamon, stir together and set aside.
In a medium mixing bowl combine flour, cocoa powder, baking powder, salt, remaining 1 teaspoon cinnamon and remaining 1 cup sugar. Sift together to combine.
In a small mixing bowl whisk together egg, milk, oil and vanilla extract. Stir by hand into flour mixture until combined.
Pour half of the batter into the prepared loaf pan. Sprinkle with half of the cinnamon and sugar mixture.
Add the remaining batter, using a butter knife swirl batter. Then top with the remaining cinnamon and sugar mixture.
Place in the preheated oven and bake for 45 minutes or until a toothpick inserted in the center comes out clean.
Cool loaf pan on cooling rack for 10 minutes.
Remove loaf from pan onto a large plate. The loose cinnamon and sugar will come off onto the plate.Carefully press all the sides of the bread onto the cinnamon and sugar that comes off onto the plate. Slice and serve.