Preheat your oven to 350 degrees. Place two 5" heart pans on a baking sheet, set aside.
Whisk the flour, granulated sugar, 1 tablespoon of the cocoa powder, baking powder and salt together in a medium bowl.
Add the half & half, vegetable oil, and vanilla, and stir until there are no lumps.
Stir in the chocolate chips, if desired.
Pour batter into the ungreased pans.
In a small bowl, mix together the brown sugar and remaining 2 tablespoons of cocoa powder. Sprinkle over the batter, dividing evenly between the pans.
Pour half the hot water (about 1/3 cup each) over the brown sugar topping in each heart pan. Carefully move the baking sheet holding the pans onto the middle rack of your preheated oven.
Bake for 35-40 minutes. The top should be dry, but not browned.
Let cool slightly, add a scoop of ice cream, and enjoy!
Notes
If you prefer, you can add chopped nuts in place of the chocolate chips.