Equipment
* optional
Ingredients
Red Velvet Cake Layers
- 750 g all-purpose flour
- 900 g caster sugar
- 45 g cocoa powder
- 15 g baking soda
- 350 g unsalted butter, room temperature
- 6 large eggs, room temperature
- 300 ml vegetable oil
- 720 ml buttermilk, room temperature
- 30 ml white vinegar
- 30 ml red gel food coloring
- 15 ml vanilla extract
Cream Cheese Filling
- 500 g cream cheese, softened
- 250 g unsalted butter, room temperature
- 800 g icing sugar, sifted
- 15 ml vanilla extract
Volcano Exterior Frosting
- 400 g unsalted butter, room temperature
- 800 g icing sugar, sifted
- 5 ml black gel food coloring
Lava and Decor
- 200 g white chocolate, finely chopped
- 70 ml heavy cream
- 5 ml red gel food coloring
- 150 g chocolate cream cookies
- 1 clean plastic dinosaur toy
Nutrition (per serving)
Method
Preheat oven to 175°C (350°F). Grease and line three 20cm round pans and two 15cm round pans with baking paper.
In a large mixing bowl, sift together the all-purpose flour, cocoa powder, and baking soda. Set aside.
In the bowl of a stand mixer, cream the 350g butter and caster sugar on medium speed until pale and fluffy, about 4 minutes.
Beat the eggs into the butter mixture one at a time, ensuring each is incorporated before adding the next. Blend in the vegetable oil, vinegar, red gel coloring, and vanilla extract until fully combined.
With the mixer on low speed, alternate adding the dry flour mixture and the buttermilk in three additions, beginning and ending with the dry ingredients. Mix just until smooth.
Divide the batter evenly among the five prepared pans. Bake for 35 to 40 minutes at 175°C (350°F).
Allow the cakes to cool in their pans for 10 minutes, then invert onto wire cooling racks to cool completely.
Prepare the internal filling: Beat the softened cream cheese and 250g butter until perfectly smooth. Gradually add 800g of icing sugar and 15ml vanilla extract. Beat until creamy and structured. Prepare the exterior frosting in a separate bowl: Beat the 400g butter and 800g icing sugar until fluffy, then mix in the black gel coloring incrementally until a stone grey color is achieved.
Place a dollop of frosting on a cake board. Stack the cooled cakes, starting with the three 20cm layers on the bottom and finishing with the two 15cm layers on top. Spread an even layer of cream cheese filling between each layer.
Chill the towering stacked cake in the refrigerator for 30 minutes to firm the cream cheese filling and provide stability for carving.
Using a serrated knife, carve the sides of the stacked cake downwards at an angle to create a tapered mountain shape. Carve a shallow bowl-shaped crater into the very top layer for the volcano opening.
Coat the entire exterior with the grey buttercream. Use an offset spatula to apply the frosting thickly, dragging it upwards to create rough ridges and crevices that resemble stone terrain. Chill the cake for another 30 minutes.
Make the lava ganache: Gently heat the heavy cream in a small saucepan until simmering, then pour it over the finely chopped white chocolate. Let sit for 1 minute, then mix until smooth. Stir in the red gel coloring until vibrant. Let cool to room temperature.
Carefully pour the cooled but fluid red ganache into the top crater, allowing it to overflow and run down the grey ridges of the cake to simulate flowing lava.
Scatter the crushed chocolate cookies around the base of the cake to look like disturbed earth. Wrap the lower half of the clean dinosaur toy tightly in food-safe cling film and press it firmly into the top crater so it appears to be erupting from the lava.
Chef's Notes
- When carving the volcano, save the cake scraps. They can be crumbled and mixed with leftover frosting to make cake truffles, or coated in leftover grey buttercream to act as extra boulders around the base.
- A central wooden dowel driven through all the layers before carving will provide critical stability for tall sculptural cakes, ensuring the layers do not slide when pressure is applied with the serrated knife.
- For the most realistic rocky texture, try briefly heating your offset spatula under hot water and drying it before using it to gouge and pull at the chilled grey buttercream, creating distinct ledges and crevices.
- Always wrap the legs or base of any plastic toy tightly in food-safe cling film before inserting it into the cake to prevent non-food-safe plastics or factory paint from coming into direct contact with the dessert.
Storage
Refrigerator: 5 days — Store in a tall cake box to protect decorations from being crushed.
Freezer: 1 month — Freeze uncarved cake layers individually wrapped in double layers of plastic film.
