### Instructions:
1. **Preheat & Prepare:** Preheat your oven to 350°F (175°C). Lightly grease a 9×9 inch baking dish.
2. **Combine Dry Cake Ingredients:** In a large bowl, whisk together the flour, granulated sugar, 2 tablespoons cocoa powder, baking powder, and salt.
3. **Combine Wet Cake Ingredients:** In a separate medium bowl, whisk together the milk, melted butter, and vanilla extract.
4. **Combine Cake Mixtures:** Pour the wet ingredients into the dry ingredients and mix until just combined. Do not overmix.
5. **Spread Batter:** Pour the cake batter evenly into the prepared baking dish.
6. **Prepare Topping:** In a small bowl, whisk together the brown sugar and ¼ cup cocoa powder until well combined.
7. **Sprinkle Topping:** Evenly sprinkle the brown sugar and cocoa mixture over the cake batter in the baking dish. Do not stir.
8. **Add Hot Water:** Carefully and slowly pour the hot water over the entire surface of the cake batter. Again, do not stir.
9. **Bake:** Bake for 30-35 minutes, or until the cake portion is firm to the touch and the pudding has set underneath. The top should have a slightly crinkled, fudgy appearance.
10. **Serve:** Let the cake cool for 10-15 minutes before serving warm. This allows the pudding to thicken slightly.
### Short Tips:
* For an extra decadent treat, serve your Hot Fudge Chocolate Pudding Cake with a scoop of vanilla ice cream or a dollop of whipped cream.
* Make sure your water is truly hot (steaming) for the best pudding layer consistency.
* Resist the urge to stir the topping or hot water – this is key to the magical separation of cake and pudding!
* Leftovers can be reheated gently in the microwave for a warm, fudgy dessert experience.
