🛒 Ingredients
For the Blue Velvet Sponge:
- 2 ½ cups all-purpose flour
- 2 tbsp unsweetened cocoa powder (for that signature velvet flavor depth)
- 1 tsp baking soda
- 1 tsp baking powder
- ½ tsp salt
- 1 ½ cups granulated sugar
- 1 cup vegetable oil
- 2 large eggs, room temperature
- 1 cup buttermilk, room temperature
- 1 tbsp vanilla extract
- 1 tsp white vinegar
- Royal Blue & Violet gel food coloring (blended to achieve the deep indigo hue in image_15ea65.jpg)
For the Blueberry Compote Filling:
- 2 cups fresh or frozen blueberries
- ¼ cup granulated sugar
- 1 tbsp lemon juice
- 1 tbsp cornstarch dissolved in 1 tbsp cold water
For the Lavender Buttercream Frosting:
- 1 ½ cups (3 sticks) unsalted butter, softened
- 4 to 5 cups powdered sugar
- 3 tbsp heavy cream
- 1 tsp pure vanilla extract
- ½ tsp culinary lavender paste (or 1 tbsp culinary lavender buds steeped in the heavy cream and strained)
- A drop of violet and blue gel food coloring
👩🍳 Instructions
Step 1: Prep and Preheat
Preheat your oven to 350°F (175°C). Grease three 6-inch or two 8-inch round cake pans and line the bottoms with parchment paper.
Step 2: Bake the Sponge Layers
In a medium bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt. In a large bowl, beat the sugar, vegetable oil, and eggs until smooth. Mix in the buttermilk, vanilla, vinegar, and enough blue and violet gel coloring to create a dark purple-blue batter. Gradually fold in the dry ingredients. Divide evenly between your pans and bake for 25 to 30 minutes (or until a toothpick comes out clean). Cool completely.
Step 3: Simmer the Blueberry Filling
In a small saucepan, combine the blueberries, sugar, and lemon juice over medium heat. Cook for 5 to 6 minutes until the berries burst. Stir in the cornstarch slurry and simmer for 1 more minute until thickened. Remove from heat and let cool completely.
Step 4: Whip the Lavender Buttercream
Beat the softened butter for 3 minutes until pale and fluffy. Gradually add the powdered sugar, heavy cream, vanilla, and lavender paste. Whip on high for another 2 minutes. Reserve a portion of frosting and tint it a deeper violet/teal shade to recreate the beautiful piped details and dark borders shown in image_15ea65.jpg.
Step 5: Assemble and Decorate
Place your first cake layer down. Pipe a ring of buttercream around the top edge to act as a dam, then spoon the cooled blueberry compote inside. Top with the next cake layer and repeat. Frost the exterior with a smooth coat of buttercream.