This is from the book 'Death by Chocolate', written by the people at the Trellis restaurant (picked it up for AU$5 off Ebay!). This is straight from the book.
"Hot" Chocolate Cake
10 oz plus 1 tablespoon plain flour
1 1/2 tsp baking powder
1 tsp bicarbonate of soda
1 tsp salt
3 1/2 oz plain chocolate, broken into 1/2 oz. pieces
1 1/2 oz unsweetened chocolate, broken into 1/2 oz. pieces
2 fl. oz. brewed coffee
2 tbsp orange juice
1 tsp orange zest
1 tsp instant espresso powder
1 tsp cinnamon
1/2 tsp cayenne pepper
1/4 tsp crushed black pepper
6 1/2 oz. unsalted butter
8 oz. soft light brown sugar
4 eggs
4 fl. oz. sour cream
4 oz. pecan pieces, chopped into 1/8 inch pieces
Preheat oven to 350 degrees.
Combine the 10 ounces of flour, baking powder, bicarb soda and salt in a stainless steel bowl. Set Aside.
Heat 1 inch of water in the bottom half of a double boiler over medium heat. Place plain chocolate, unsweetened chocolate, coffee, orange juice, orange zest, espresso powder, cinnamon, cayenne and black pepper in the top half of the double boiler. Tightly cover the top with clingfilm and heat for 6-8 minutes. Remove from heat and stir until smooth.
Coat a 9 inch x 13 inch x 2 inch rectangular cake pan with 1/2 ounce of butter. Flour the pan with the extra tablespoon of flour, shaking out the excess.
Place the brown sugar and remaining butter in the bowl of a mixer fitted with a paddle. Beat the sugar and butter on low for 3 minutes, then on high for 2 minutes. Scrape down the sides. Beat on high until light and fluffy, about 3-4 minutes.
Add the eggs, one at a time, while beating on high for 1 minute after adding each egg. Scrape down the bowl before adding each egg. Add the melted chocolate and beat on high until thoroughly combined, about 30 seconds. Scrape down the bowl. Add the flour mixture and beat on low for 30 seconds. In the stainless steel bowl, vigorously whisk the sour cream. Add the sour cream to the cake mixture and combine on high for 10 seconds. Remove the mixing bowl from the mixer and use a rubber spatula to thoroughly combine.
Pour the batter into the prepared tin, spreading it evenly, including the corners. Sprinkle the chopped pecans evenly over the top of the batter. Bake in the preheated oven, until a skewer inserted in the centre comes out clean, about 35-40 minutes. Remove the cake from the oven and cool in the tin at room temperature for 15 minutes.
Remove the cake from the tin and place upright on a cutting board. Use a serrated slicer to cut the cake lengthwise across the centre. To yield 12 portions, make 5 cuts across the width of the cake at 2 1/4 inch intervals. For 18 servings, cut the cake lengthwise into thirds, then make 5 cuts across the width of the cake at 2 1/4 inch intervals.
The book recommends serving it with a chocolate sauce.