Here comes the best part! Let me break this down into easy steps for you.

Start off by preheating your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans. You want to ensure your cake comes out easily once it's baked.

In a large bowl, whisk together the all-purpose flour, cocoa powder, baking powder, baking soda, sea salt, and ground cinnamon. This creates a dry mixture that’s well-combined. Remember, the cocoa powder can be a little clumpy, so make sure it’s all broken up nicely.

In another bowl, mix the sugar and vegetable oil until it's blended. Then add the eggs one by one, mixing well after each addition. Next, stir in the sour cream and vanilla extract. Make sure everything is incorporated nicely.

Gradually add the dry ingredients mixture to the wet ingredients, alternating with the whole milk. Start and end with the dry ingredients to help with proper mixing. Once you're close to finished, carefully add the freshly boiled water. This will make your batter very liquid, which is perfect for a moist cake.

Divide the batter evenly between the prepared pans. Bake for around 30-35 minutes or until a toothpick inserted in the center comes out clean. Be cautious not to over-bake; a little moistness is your friend here!

Once baked, let the cakes cool in the pans for about 10 minutes before transferring them to a wire rack. Allow them to cool completely. This step is crucial as it prevents any melting of your decorations later on.

Now, it’s time to bring Pooh to life! Use buttercream frosting tinted in soft yellows and browns. You can shape the frosting into Pooh's face, complete with little ears atop the cake. You might even consider using a honey glaze made from powdered sugar, milk, and a hint of honey to drizzle over the top.