This moist layered pound cake makes the perfect finale to a summer barbecue. To tint the vanilla buttercream a pretty shade of pale purple, stir in a little fresh blackberry juice, which you can make by pressing a handful of blackberries through a fine-mesh sieve.
Lavender-Blackberry Pound Cake
For the cake:
- 1 1/2 cups (3/4 lb./375 g) unsalted butter, at room temperature, plus more for greasing
- 3 cups (15 oz./470 g) all-purpose flour, plus more for dusting
- 1 1/2 tsp. baking powder
- 3/4 tsp. kosher salt
- 2 1/4 cups (18 oz./560 g) sugar
- 1 tsp. dried lavender, very finely minced
- 4 eggs plus 1 egg white
- 1 Tbs. vanilla extract
- 1 cup (8 fl. oz./250 ml) whole milk
- 5 pints (2 1/2 lb./1.25 kg) blackberries
- 1 Tbs. sugar
- Fresh lavender or other edible flowers for decorating
For the vanilla buttercream:
- 3 egg whites
- 1 cup (8 oz./250 g) sugar
- 1 tsp. vanilla extract
- 1 cup (8 oz./250 g) unsalted butter, at room temperature
1. Preheat an oven to 350°F (180°C). Grease two 8-inch (20-cm) round cake pans, line the bottoms of the pans with parchment paper, then grease the parchment. Dust with flour, then tap out any excess.
2. In a large bowl, sift together the flour, baking powder and salt. Set aside. In a food processor, combine the butter, sugar and dried lavender and pulse until well combined, about 45 seconds. Transfer the butter mixture to the bowl of a stand mixer fitted with the paddle attachment. On medium speed, beat in the eggs and egg white one at a time, beating well after each addition, then beat in the vanilla. Reduce the speed to low and add the flour mixture in 3 additions, alternating with the milk and beginning and ending with the flour, and beat until combined.
3. Arrange a single layer of blackberries on the bottom of the prepared pans so that they cover the entire surface (about 2 pints/1 lb./500 g per pan); reserve the remaining berries for decorating. Divide the batter evenly between the pans and spread evenly. Tap the pans on the counter to submerge the berries in the batter. Bake until a toothpick inserted into the center of the cakes comes out clean, about 50 minutes. Transfer the pans to wire racks and let cool for 10 minutes, then invert the cakes onto the racks and let cool completely.
4. To make the vanilla buttercream, combine the egg whites and sugar in the bowl of a stand mixer and set over but not touching barely simmering water in a saucepan. Cook, whisking constantly, until the mixture is hot to the touch, about 160°F (71°C).
5. Attach the bowl to the stand mixer fitted with the whisk attachment, add the vanilla and beat on medium-high speed until the mixture reaches room temperature, about 15 minutes. Switch to the paddle attachment, add the butter a few tablespoons at a time, and beat on low speed until incorporated. If the buttercream becomes grainy, raise the speed to high and beat until smooth, about 1 minute. Divide the buttercream equally between two bowls. Set aside one of the bowls for another use.
6. To assemble the cake, place 1 cake layer, blackberry side up, on a serving plate. Spread half of the buttercream evenly over the cake, then top with the other layer, blackberry side up. Spread the remaining buttercream over the top of the cake. In a small bowl, toss together the remaining blackberries and the sugar until evenly coated. Arrange them in a ring around the outside edge of the cake, decorate with fresh lavender and serve. Serves 12.
Discover a swoon-worthy collection of cakes in the stunning cookbook
Favorite Cakes, by the cooks of the Williams Sonoma Test Kitchen.