Preheat your oven to 350°F (175°C) and grease a 9-inch round cake pan.

In a large mixing bowl, whisk together flour, cocoa powder, sugar, baking powder, and salt until combined.

Add softened butter, eggs, and vanilla extract to the dry ingredients and mix until smooth.

Gradually stir in boiling water to activate cocoa for a smooth batter.

Pour the batter into the greased pan and bake for 30–35 minutes or until a toothpick comes out clean.

Let the cake cool in the pan for 10 minutes before inverting onto a wire rack to cool completely.