Chocolate Orbit Cake with Blackberry-Cassis Sauce

This cake is nothing short of sensational.  It's rich, decadent, and well simply amazing.  The blackberry-cassis sauce is the perfect complement to the cake.  I scaled the cake recipe down (original below) and made a full version of the sauce, so there's plenty left over.  I can't wait to find something to do it justice.

I used a mixture of semisweet and regular dark chocolate and it came out just fine.  The original sauce recipe called for 1 bag of frozen blackberries and 1 - 2 baskets of fresh blackberries.  I had no idea how much that should be (and don't have easy access to frozen foods right now), so I just used 12 ounces of fresh blackberries.

Chocolate Orbit Cake with Blackberry-Cassis Sauce (from Desserts for Breakfast) (from Room for Dessert by David Lebovitz)

Ingredients
for cake
1/2 pound butter, in small chunks
12 oz bittersweet chocolate, chopped
1 cup sugar
6 eggs
for sauce
12 ounces fresh blackberries
1/3 cup creme de cassis
1/4 cup sugar, approx.
juice of 1/2 lemon
zest of 1 lemon
1 tspn cornstarch

Cake directions
1. Preheat oven to 350 degrees F.
2. Line the bottom of a 9" round pan with parchment paper and butter the bottom and sides.
3. Combine the butter and chocolate in a double boiler.  Cook until melted. (I just microwaved it together to save time.)
4. In a separate bowl, whisk together the sugar and the eggs.
5. Whisk in the melted chocolate to the sugar and eggs.
6. Pour the batter into the prepared cake pan, and place this cake pan into a water bath, with warm water reaching about half-way up the sides.
7. Cover tightly with foil.
8. Bake in the oven for 1 hour and 15 minutes, until the cake appears set and your finger comes away clean when you touch the center.
9. Remove from oven and water bath and let cool completely. 
Sauce directions
1. In a medium saucepan over medium heat, heat the blackberries, until they begin to release their juices.
2. Add in the creme de cassis, sugar, lemon zest, and lemon juice and bring to a simmer.
3. When the liquid begins to simmer, spoon about 1/4 cup of the liquid into a small bowl.  Add the cornstarch to the liquid in the bowl and whisk thoroughly until the cornstarch is dissolved.  Return the cornstarch mixture to the berries cooking in the saucepan.
4. Bring the mixture to a boil and allow to boil for about a minute.
5. Reduce heat to a simmer until the liquid begins to be syrupy.  Remove from heat--serve warm immediately or reheat in microwave before serving (if you are freezing the sauce for later use).