Preheat oven to 350F (no fan) and prepare 3 8" pans with parchment paper and butter.

In a bowl, combine flour, baking powder, baking soda, granulated sugar, light brown sugar, and salt. Whisk together until no lumps remain.

In a separate bowl, whisk together eggs, vegetable oil, buttermilk, and sour cream until smooth.

Add the dry ingredients to the wet in 2 additions, and gently whisk and fold until just combined. Do not overmix.

In a separate small bowl, combine cocoa powder and instant coffee. Pour over boiling water and whisk until smooth.

Pour cocoa mixture into the batter and gently fold until a chocolate cake batter forms.

Divide the batter evenly between the 3 prepared cake pans.

Bake for about 22-24 minutes until a toothpick inserted in the center comes out with light moist crumbs.

Let the cakes cool in the pans for 20 minutes, then carefully remove and place on a wire rack. Let cool completely (recommended to refrigerate for 1 hour).

For the frosting, add chocolate and corn syrup to a saucepan and heat over the lowest flame, stirring constantly until melted. Set aside.

In the bowl of a stand mixer, add room temperature cream cheese and sift in cocoa powder, powdered sugar, and salt. Mix on medium speed until creamy (1-2 minutes).

Add heavy cream and whisk again on low speed until fluffy. Scrape the bowl in between.

Slowly pour in the melted chocolate while whisking on low speed until fully combined.

Let the frosting cool until spreadable, about 30 minutes at room temperature (or in the fridge).

Once the cakes and frosting have cooled, use a serrated knife to trim off the domes from the cakes.

Layer the cakes with a generous amount of frosting in between. Cover the cake with a thin layer of frosting (crumb coat) and refrigerate for 20 minutes.

Slather on the remaining frosting all over the cake.

Serve at room temperature. For a shiny look on the cake, use a blow dryer on the lowest setting held 1 foot away from the cake.