Preheat the oven to 320°F. Grease a 9x5-inch loaf pan with vegetable oil and line with parchment paper so that it overhangs the two long sides of the pan.
Beat the eggs and sugar together until thick and lightened in color, about 5-7 minutes.
In a large microwave-safe bowl, combine the butter and chopped chocolate. Heat in the microwave at 100% power in 45 second intervals. Stir well with each heating, until the mixture is melted and can be stirred smooth.
Gradually add the melted chocolate mixture a little at a time. Mix in the ground walnuts and salt. Scrape down the bowl to make sure all the ingredients are incorporated and pour into the pan.
Place a large roasting pan on the center rack in the oven. Place the loaf pan in the pan and fill with hot water to about 1/3 up the loaf pan. Bake for 30 minutes at 320°F. Increase temperature to 350°F and bake for about 20 minutes more, until the cake is set. The cake should have a slight dip in the center, this is normal. Allow the cake to cool completely in the pan.
For the toppings: Combine the chocolate chips and cream in a large microwave-safe glass measure. Microwave at 100% power for 1 minute. Allow the hot mixture to stand for 1 minute. Whisk together until a glossy ganache forms; pour over the cooled cake in the pan. Immediately garnish with pearls or sprinkles. Let stand until set, or refrigerate to speed setting.
For the coulis: combine the raspberries and 1 cup of sugar in a medium saucepan. Cook until the raspberries give off their juices, about 7 minutes. Add more sugar to taste. Cook until the sugar is completely dissolved. Remove from the heat and let cool.
Place the mixture in a food processor or blender and pulse until pureed.
Place a sieve over a large bowl and pour the raspberry puree through; press using the back of a spoon or rubbery spatula to force the liquid through the sieve and discard the solids.
Stir in the tablespoon of liquor if using. Transfer the coulis to a jar or cover the bowl and store in the refrigerator until ready to serve.
Run a knife between the cake pan and the cake and remove from the pan using the overhanging parchment paper; peel away the paper and discard. Allow the cake to come to room temperature before serving.
To serve, pour the raspberry coulis on dessert dishes and plate chocolate loaf slices on top. This cake is also excellent served with unsweet whipped cream or vanilla ice cream.