- Cake:
- 3/4 cup walnuts
- 1 cup whole-wheat pastry flour (see Ingredient note)
- 3/4 cup all-purpose flour
- 1 1/2 teaspoons baking powder
- 1/2 teaspoon baking soda
- 1/4 teaspoon salt
- 1 cup buttermilk
- 1/4 cup mild olive oil or canola oil
- 4 teaspoons very finely chopped fresh rosemary
- 1 teaspoon vanilla extract
- 1/2 teaspoon freshly grated lemon zest
- 2 large eggs, at room temperature (see Tip)
- 2 large egg whites, at room temperature (see Ingredient Note)
- 1 1/4 cups sugar
- Vanilla Cream:
- 1 cup low-fat or nonfat vanilla yogurt
- 1/4 cup whipping cream
- 2 1/2 teaspoons confectioners' sugar, plus more for dusting (optional)
- 2 cups mixed fresh berries (blueberries, raspberries, blackberries)
- Rosemary sprigs for garnish
- Position rack in center of oven; preheat to 350 degrees F. Coat a 10-inch (12-cup) Bundt pan, preferably nonstick, with cooking spray.
- Spread walnuts in a small baking pan and toast in the oven until fragrant, 4 to 6 minutes. Let cool.
- Place walnuts, whole-wheat flour, all-purpose flour, baking powder, baking soda and salt in a food processor; process until walnuts are finely ground.
- Combine buttermilk, oil, rosemary, vanilla and lemon zest in a glass measuring cup.
- Place eggs, egg whites and sugar in a large mixing bowl. Beat with an electric mixer on high speed for 5 minutes. The mixture should be thickened and pale.
- With a rubber spatula, alternately fold the dry ingredients and buttermilk mixture into the egg mixture, making 3 additions of the dry and 2 additions of liquid. Scrape the batter into the prepared pan, spreading evenly.
- Bake the cake until the top springs back when touched lightly and a toothpick inserted in the center comes out clean, 35 to 40 minutes. Let cool in the pan on a wire rack for 5 minutes. Loosen the edges and turn the cake out onto the rack to cool completely.
- Meanwhile, make Vanilla Cream: Line a sieve or colander with cheesecloth and set over a bowl, leaving at least 1/2-inch clearance from the bottom. (Alternatively, use a coffee filter lined with filter paper.) Spoon in yogurt, cover and let drain in the refrigerator for 1 hour. Discard whey.
- Whip cream in a small bowl until soft peaks form. Add sugar, if using, and continue whipping until firm peaks form. Fold in drained yogurt.
- To serve, set the cake on a platter and dust with confectioners' sugar. Garnish with berries and rosemary sprigs. Serve each piece with a dollop of Vanilla Cream and some berries.