Preheat oven to 350℉ and grease a deep 8x8 or 9x9 inch baking dish.
In a medium sized mixing bowl, prepare the brownie mix as instructed on package; set aside (don't pour into the pan yet!).
1 10.25-ounce pkg fudge brownie mix*
In another bowl, combine the dry topping ingredients (brown sugar, sugar, cocoa powder, cornstarch, and salt) then stir in the boiling water.
1/2 cup brown sugar, 1/4 cup sugar, 2 tablespoons cocoa powder, 1/4 teaspoon salt, 1 cup boiling water, 1 tablespoon cornstarch
Pour the hot mixture into the bottom of the prepared pan.
Pour the brownie batter on top.
Bake for 25-30 minutes. The top should be shiny and there should be a fudgy pudding bubbling around the edges of the pan.
Let it cool for 10-15 minutes then garnish with a dusting of powdered sugar and serve warm with ice cream, if desired.
powdered sugar