Preheat the oven to 350 degrees.
Combine the flour, sugar, cocoa powder, baking soda, baking powder, salt, and cinnamon in a bowl. Whisk together to fully combine the ingredients and break up any lumps.
Add in eggs, oil, and buttermilk. Stir until almost combined. There should still be some clumps of flour throughout.
Then stir in the cup of boiling water. Gently, stir in the water. Be careful! Some water may splash out on you while stirring!
Line a cupcake dish with liners and fill about 2/3’s of the way full.
Bake for about 18-20 minutes, until a toothpick inserted comes out clean.