Prep the pans:
Preheat oven to 350°F (no fan). Butter and line three 8-inch cake pans with parchment paper.

Mix dry ingredients:
In a large bowl, whisk together flour, both sugars, baking powder, baking soda, and salt.

Mix wet ingredients:
In a separate bowl, whisk eggs, oil, buttermilk, and sour cream until smooth.

Combine:
Add the dry ingredients to the wet in two batches. Gently whisk or fold until just combined—don’t overmix!

Bloom the cocoa:
In a small bowl, mix cocoa powder and instant coffee. Pour boiling water over and whisk into a shiny paste.

Create the batter:
Pour the cocoa mixture into the main batter and fold gently until smooth and fully combined.

Bake:
Divide batter evenly between the three pans. Bake for 22–24 minutes or until a toothpick comes out with moist crumbs.

Cool:
Let cakes cool in the pans for 20 minutes, then transfer to a wire rack. Chill for at least 1 hour before frosting.

Make the frosting:
Melt the dark chocolate with corn syrup until smooth. In a large bowl, beat cream cheese, cocoa powder, powdered sugar, and salt. Add melted chocolate and mix until combined. In a separate bowl, whip the cream to soft peaks, then fold it into the chocolate mixture.

Assemble:
Stack and frost the chilled cake layers with the chocolate fudge frosting. Slice, serve, and enjoy the magic.