Turn your oven on to 350°F (175°C). Grease and flour a 9×13-inch baking pan so the cake won’t stick.

In a medium saucepan, melt 1 cup of butter over medium heat. Stir in ½ cup of cocoa powder. Once that’s smooth, slowly pour in 1 cup of boiling water, stirring constantly. When everything’s well mixed and smooth, take it off the heat and let it cool slightly.

In a large mixing bowl, combine 2 cups of sugar, 2 cups of all-purpose flour, 1 teaspoon of baking soda, ¼ teaspoon of salt, and 1 teaspoon of ground cinnamon. Give it a good stir to mix everything evenly.

Pour the warm (not hot) cocoa mixture into the bowl with the dry ingredients. Stir gently until it all comes together. Don’t beat it just mix until blended.

In a small bowl, whisk together 1 beaten egg, ½ cup of buttermilk, and 2 teaspoons of vanilla extract. Add that to the batter and stir everything until it’s smooth.

Now, gently fold in the shredded apples and ¼ cup of chopped walnuts. Mix just enough to spread them evenly through the batter.

Pour the batter into your prepared pan and smooth the top. Bake for 30 to 35 minutes, or until a toothpick poked in the middle comes out clean.

Take the cake out of the oven and place it on a wire rack. Leave it in the pan while you make the frosting.

In a small saucepan, melt ½ cup of butter. Stir in ¼ cup of cocoa powder and 6 tablespoons of milk. Heat it gently, stirring until smooth.

Remove from the heat and whisk in 3½ cups of powdered sugar and 1 teaspoon of vanilla extract. Keep whisking until the frosting is creamy and smooth.

Pour the warm frosting over the still-warm cake. Spread it out evenly, then sprinkle 1 cup of chopped, toasted pecans on top.

Allow the cake to cool all the way before slicing. Serve when ready and enjoy!