Preheat the oven to 320°F.
Grease a 9x5-inch loaf pan with vegetable oil and line with parchment paper leaving extra paper hanging from the sides of the pan.
In a large bowl, beat the eggs and sugar together with a whisk or electric mixer until reach a smooth, thick and lightened batter.
In a large microwave-safe bowl, combine the butter and chopped chocolate. Heat in the microwave at full power in 30 seconds intervals two or three times until melted, stirring with a rubber spatula.
Gradually add the melted chocolate to the egg mixture a little at a time. Mix in the ground walnuts and salt. Scrape down the bowl with the rubber spatula to incorporate it well. Transfer the cake batter to the loaf pan.
Place a large roasting pan on the center rack of the oven. Place the loaf tin in the pan and fill with hot water to about 1/3 up the loaf pan.
Bake for 30 minutes at 320°F then 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. Remove and allow it to cool completely in the pan.
To make the ganache: Combine the chocolate chips and cream in a large microwave-safe bowl. Microwave at full power for 1 minute. Whisk together until a glossy ganache forms.
Pour it over the cooled cake in the pan. Let it stand until set, or refrigerate to speed this process.
To make the raspberry coulis: combine the raspberries and 1 cup of sugar in a medium saucepan. Cook until the raspberries release their juices, for about 7 minutes. Add sugar to taste if you like. Cook until dissolve. 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.
Transfer the coulis to a jar with an airtight lid and keep it in the fridge until ready to serve.
Remove the cake from the pan using the overhanging parchment paper. Peel away the paper and discard it.
To serve, pour the raspberry coulis on dessert dishes and plate cake slices on top.