Preheat your oven to 350°F and lightly grease a small cake pan or ramekin. This simple step helps your mini chocolate cake release easily after baking and keeps the edges from sticking.

In a mixing bowl, add flour, sugar, cocoa powder, baking powder, baking soda, and salt. Whisk everything together until evenly combined and smooth with no visible lumps remaining.

Pour in milk, vegetable oil, and vanilla extract into the dry mixture. Stir gently using a whisk or fork until the batter becomes smooth, thick, and fully combined without overmixing.

Slowly add the hot water while stirring continuously. The batter will look thinner, which is normal. This step ensures your mini chocolate cake stays soft and moist after baking.

Pour the prepared batter into your greased pan. Gently tap the pan on the counter to remove air bubbles and help the cake bake evenly with a smooth top surface.

Place the pan in the preheated oven and bake for about 18 to 22 minutes. Check doneness using a toothpick, it should come out clean when the cake is ready.

Let the cake cool in the pan for about 10 minutes. Carefully remove it and place on a rack. Serve warm or at room temperature with your favorite toppings.