Preheat the oven to 350°F (180°C). Grease and line 2 (9-inch) round cake tins.

In a large bowl, sieve together flour, sugar, cocoa powder, cinnamon, baking soda, and salt.

In a separate jug, whisk together eggs, oil, buttermilk, food coloring, and vanilla.

Whisk the wet ingredients into the flour mixture. Take care not to overmix the batter as it can toughen the cake. Divide the batter evenly into the prepared pans.

Bake for about 30-35 minutes or until a toothpick inserted in the center comes out clean. Let cakes cool in the tin then turn out onto a rack to cool completely.

How to Make Ermine Frosting: In a medium saucepan over medium heat whisk together the sugar, flour, and salt. Cook for roughly 2 minutes to toast the flour.

Slowly add in the milk, whisking to combine. Whisk continuously until the mixture simmers and has thickened and is the consistency of thick pudding. Lay plastic wrap directly on the surface of the mixture and set aside to cool completely, roughly 2 hours. (This mixture can be made the day before and kept in the fridge.)

Next, add the butter to the bowl of a stand mixer and whisk on high until light and fluffy, roughly 2-3 minutes. Slowly add in the cooled flour mixture one spoon at a time as you whip. Lastly, add in the vanilla and whip until the frosting is light and fluffy. Set aside until needed.

Decorating the Cake: Place 1 layer, flat side up, on a flat plate or cake pedestal. Put a dollop of Ermine frosting in the center of the cake and with an offset spatula spread it all the way to the edges of the cake creating an even layer of frosting. Repeat with the next layer.

On top, spread a big dollop of frosting. Work the excess frosting from the top down the sides, roughly covering the cake with a thin layer of frosting. This step is just the first layer known as the crumb layer. Don’t worry, it’s not supposed to be beautiful.

Put the cake in the fridge and let the crumb layer set for a minimum of 45-60 minutes. (this will make the finished product look really clean.)

Take the cake from the fridge and put on another, final layer of frosting. Start with a dollop on top again and work the frosting down the sides covering the whole cake. Decorate by sprinkles a few extra cake crumbs around the top of the cake if you have them. Keep this cake at room temperature for up to 4 days. It just gets better as it sits.