Preheat oven to 350°F and line a 9-inch round cake pan6 with parchment paper and grease with non-stick spray.
Melt chocolate and butter separately on the microwave on 30-second intervals, stirring between each one. Add them to a large mixing bowl along with the sugars, vanilla, salt, and coffee. Mix until fully combined.
Add the eggs one at a time whisking between each addition until no yolk is visible.
Whisk in the cocoa powder until completely combined.
Pour the batter into the prepared cake pan and bake for 30 to 32 minutes, a toothpick or cake tester should come out mostly clean with some crumb/chocolate.7,8
Remove from the oven and allow to cool completely in the pan before gently inverting onto a plate or cake stand.9
Serve with raspberry filling, chocolate ganache, whipped cream, powdered sugar, and/or fresh fruit or store for future enjoyment.10,11,12