Let’s bake this famously moist chocolate cake:

1. Prepare Oven and Pans:

Preheat oven to 350°F (175°C / 170°C fan).

Grease two 8-inch or 9-inch round cake pans well. Line the bottoms with parchment paper rounds. Set aside.

2. Whip Eggs and Sugar:

In a stand mixer bowl with the whisk attachment (or large bowl with hand mixer), whip the room temperature eggs, granulated sugar, salt, and vanilla extract on medium-high speed until the mixture is airy, light in color, and somewhat foamy (ribbon stage).

3. Add Fats and Dairy:

Add the room temperature sour cream (or coconut cream) and the vegetable oil to the egg mixture.

Mix slowly at medium speed just until they are absorbed and the mixture is uniform.

4. Combine Dry Ingredients:

In a separate large bowl, sift together the all-purpose flour, cocoa powder, baking soda, and baking powder. Whisk briefly to combine.

5. Combine Wet and Dry:

Add the sifted dry ingredients to the wet mixture in the mixer bowl.

Mix slowly (low speed) until almost uniform – some streaks of flour might remain.

6. Add Warm Water/Coffee:

With the mixer still on low speed, slowly pour in the lukewarm water (or hot coffee).

Continue mixing slowly only until you get a completely uniform batter. Scrape down the sides and bottom of the bowl with a spatula to ensure everything is incorporated. The batter will be relatively thin.

7. Bake the Cake Layers:

Pour the batter evenly into the two prepared cake pans.

Bake for 30-35 minutes (adjust time based on pan size – start checking earlier for 8-inch), or until the cake is visibly risen, feels steady to the touch, and a skewer or toothpick inserted in the center comes out with moist crumbs attached (not wet batter).

8. Cool the Cakes:

Cool the cakes completely in the pans on wire racks. This type of moist cake benefits from cooling fully in the pan to maintain structure. Once completely cool, carefully invert cakes, remove parchment.

9. Make the Chocolate Ganache:

While cakes cool (or after), make the ganache. Chop the dark chocolate finely and place it in a medium heatproof bowl.

Heat the heavy whipping cream in a small saucepan over medium heat until it just comes to a simmer (bubbles form around the edges). Do not boil vigorously.

Pour the hot cream over the chopped chocolate. Let it sit undisturbed for 4-5 minutes to allow the heat to melt the chocolate.

Starting from the center, gently whisk the mixture until the chocolate is completely melted and the ganache is uniform, smooth, and shiny.

10. Cool Ganache to Spreading Consistency:

Let the ganache cool completely at room temperature for 4-5 hours, stirring occasionally. It needs to thicken to the consistency of a thick paste or very soft peanut butter – firm enough to spread and hold its shape but not hard. (You can speed this up by chilling in the refrigerator, but you MUST stir it vigorously every 10-15 minutes to ensure it cools evenly and doesn’t harden too much).

11. Assemble the Cake:

Using a long, serrated knife, level the tops of the cooled cakes if necessary.

Place the first layer of cake on a serving plate or cake stand.

Pour or scoop about ⅓ of the cooled, spreadable ganache onto the center of the cake layer.

Using an offset spatula or palette knife, spread the ganache evenly to the edges.

Place the second layer of cake (upside down for a flat top) over the ganache.

Cover the entire cake – top and sides – with almost all the remaining ganache, smoothing it as best you can with your offset spatula or a bench scraper for a uniform layer.

12. Decorate (Optional):

Transfer the small remaining amount of ganache into a piping bag fitted with a 1 cm (approx. ½ inch) serrated or star piping tip.

Decorate the top edge or base of the cake with piped ganache stars, shells, or swirls.

13. Serve:

Serve the cake at room temperature for the best texture of both the cake and the ganache.

Keep the cake stored in a closed container at room temperature for up to a week (ganache acts as a good seal). If refrigerated, allow slices to come to room temperature for about an hour before serving.