1. Preheat the oven to 350°F (175°C) and grease your cake pan.
2. In a bowl, whisk together flour, sugar, cocoa powder, baking powder, and a pinch of salt.
3. In a separate bowl, beat eggs, then add melted butter or oil and mix well.
4. Gradually add the wet ingredients to the dry ingredients, stirring until smooth.
5. Slowly mix in milk or water to achieve the desired batter consistency.
6. Pour the batter evenly into the prepared cake pan.
7. Bake for about 30-35 minutes or until a toothpick inserted in the center comes out clean.
8. Allow the cake to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.
9. Prepare chocolate frosting by mixing butter, cocoa powder, powdered sugar, and a splash of vanilla extract.
10. Once the cake is completely cooled, spread the frosting evenly over the top and sides.
11. Slice and serve your homemade chocolate cake for a delicious treat.