First, preheat your oven to 350°F (175°C). Grease your 8-inch round cake pan with butter or non-stick spray and lightly dust it with flour. You can also line the bottom with parchment paper to ensure the cake doesn’t stick.

In a large mixing bowl, whisk together the all-purpose flour, sugar, cocoa powder, baking powder, baking soda, and salt. These dry ingredients are the base of your cake and will ensure it rises beautifully.

In another bowl, whisk together the eggs, vanilla extract, and vegetable oil until the mixture is smooth and well-combined. Add the milk and continue whisking until fully incorporated.

Gradually pour the wet mixture into the dry ingredients. Use a hand whisk or an electric mixer on low speed to combine them. Make sure not to overmix—just enough to form a smooth batter.

Here’s a little secret to making the cake extra moist: carefully add boiling water to the batter. The batter will be quite thin, but this is perfectly fine—it will create a wonderfully moist cake once baked.

Gently fold in the chopped walnuts with a spatula, making sure they are evenly distributed throughout the batter.

Pour the batter into the prepared cake pan. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Every oven is different, so keep an eye on it towards the end!

Once the cake is done, allow it to cool in the pan for 10 minutes before transferring it to a cooling rack. This will help prevent it from breaking apart.

If you’re using the chocolate frosting, prepare it while the cake cools. Simply beat together the softened butter, powdered sugar, cocoa powder, and vanilla extract. Gradually add milk until you reach your desired consistency.

Once the cake is completely cool, spread the frosting generously over the top. You can also sprinkle additional chopped walnuts on top for an extra touch.