Add a scoop of vanilla ice cream and this tastes just like a hot fudge sundae from the ice cream shop. Be sure to drizzle a bit of the sauce/pudding over the ice cream for that little extra touch. As crazy (and long) as the process for this cake sounds, trust me when I say to follow the instructions. If you're not a coffee drinker, don't let the coffee in this recipe scare you away; it gives the chocolate a rich depth that will be welcomed by your tastebuds. You will not be disappointed.
Hot Fudge Pudding (from The America's Test Kitchen Family Cookbook)
6 T unsalted butter
2/3 c. cocoa powder
2 oz. semisweet chocolate, chopped
1/3 c. packed light brown sugar
1 c. sugar
3/4 c. all-purpose flour
2 tsp baking powder
1/3 c. milk
1 T vanilla extract
1/4 tsp salt
1 lg egg yolk, at room temperature
1 1/2 c. coffee, at room temperature
Adjust an oven rack to the lower-middle position and heat the oven to 325. Lightly coat an 8" square glass or ceramic baking dish thoroughly with vegetable oil spray.
Melt the butter, 1/3 c. of the cocoa, and the chocolate together in a medium bowl in the microwave, whisking often, until smooth, 1 to 3 mnutes. In a separate bowl, stir the brown sugar, 1/3 c. of sugar, and remaining 1/3 c. cocoa together until there are no clumps. Whisk the flour and baking powder together in a third bowl.
Whisk the remaining 2/3 c. sugar, milk, vanilla, and salt together in a large bowl. Whisk in the yolk, then the chocolate mixture until combined. Whisk in the flour mixture until combined.
Spread the batter in the prepared baking dish. Sprinkle the brown sugar mixture evenly over the batter. Pour the coffee gently over the brown sugar mixture. Bake until the cake is puffed and bubbling and just beginning to pull away from the side sof the baking dish, about 45 minutes, rotating the pan halfway through baking. (Do not overbake.)
Let the cake cool in the dish on a wire rack for about 25 minutes before spooning into bowls.