• Preheat the oven to 325°F. Oil and line with parchment paper either one 9-inch round cake pan or two 7-inch (18 cm) round cake pans. (I had a graduated series so mine are one 8-inch round and the top is a 6-inch round).
• Whisk the flour, baking powder, baking soda, cocoa powder, sugar and cinnamo together in in a large mixing bowl and set aside.
• In a separate mixing bowl or a large liquid measuring cup, whisk together the warm milk, the oil, eggs and vanilla.
• Make a well in the center of the dry ingredients. For a smooth, lump-free batter, pour about a quarter of the liquid ingredients into the well, and using a whisk with small, brisk circular movements, mix with just enough of the dry until you have a thick, smooth, lump-free batter in the center. Add some more of the liquid, pull in a bit more of the dry ingredients and briskly whisk again until your batter is smooth.
• Continue until all the dry ingredients have been incorporated into your batter, add any remaining liquid and mix a final time.
• Pour the batter into your prepared pan(s) and bake for about 30 minutes (for one 9-inch round pan and depending on your oven) until the center of your cake or layers is just firm to the touch, completely cooked through. The cake should start to pull away from the sides of the pan just after it is removed from the oven. Adjust your time depending on the size of your cake pans; My 8-inch one needed 25 minutes and the 6 inch one about 20 minutes.
• Remove to racks, let cool for about 10 minutes, then slide a sharp knife blade around the edges to loosen, turn the cake out onto racks, peel off the parchment paper, flip back upright and let cool completely. Serve as is with a dusting of confectioner's sugar or a drizzle of chocolate or layer it with frosting.

To Make the Cinnamon Frosting:

• Beat the butter In the bowl of an electric mixer until light and fluffy. Add the powdered sugar, vanilla, cinnamon and 1 tablespoon milk and beat on high speed until the frosting is spreading consistency. If the frosting is stiff, add a few more drops of milk, beating after each addition. Frost the cooled cake and garnish with chocolate curls.
• This recipe makes enough to frost two 9-inch layers or 24 cupcakes so you might have some leftover. I love it on graham crackers!