Delicious blueberries are at their peak right now. Our cake recipe is loaded with fresh berries and flavored with a walnut cardamom topping. Perfect with just a cup of coffee for breakfast or as a dessert. Add icing as a special treat by combining 1 cup of powdered sugar with 1 tablespoon of fresh lemon juice. Then whisk until completely smooth. Lightly drizzle the icing over your cake right before serving.
11 tablespoons unsalted butter, at room temperature, divided, plus more for greasing the pan
2 ⅓ cups plus 2 teaspoons all-purpose flour, plus more for flouring the pan
½ cup chopped walnuts
¼ cup plus ⅔ cup sugar
⅓ cup packed dark brown sugar
½ teaspoon salt, divided
½ teaspoon, plus ¼ teaspoon cardamom
2 cups fresh blueberries
2 teaspoons baking powder
½ teaspoon baking soda
½ teaspoon cinnamon
2 large eggs, at room temperature
1 teaspoon pure vanilla extract
½ cup buttermilk
Preheat the oven to 350 degrees. Butter and flour an 8×8 inch square baking pan. Place the walnuts on a sheet tray and toast in the oven for 10 minutes; remove from the oven and cool. Leave the oven on.
Put 5 tablespoons of butter, ¼ cup sugar, ⅓ cup dark brown sugar, ⅓ cup all-purpose flour, ¼ teaspoon of salt, and ½ teaspoon of ground cardamom in a food processor and pulse just until the mixture forms large clumps. Scrape into a bowl, stir in the toasted walnuts. Cover tightly and refrigerate.
Gently toss the blueberries in 2 teaspoons of the flour to coat; set aside. Whisk together the remaining 2 cups flour, the baking powder, baking soda, salt, cinnamon, and ¼ teaspoon cardamom. Set aside.
Into the work bowl of a stand mixer add the remaining 6 tablespoons of butter. With the paddle attachment beat the ⅔ cup sugar at medium speed for 3 minutes or until light and fluffy. Add the eggs one by one, beating for about 1 minute after each addition, then beat in the vanilla extract. Reduce the mixer speed to low and add the flour mixture and the buttermilk alternating between the two, beginning and ending with the dry ingredients. Blend just until you have a thick, creamy batter; do not over mix. With a rubber spatula, gently stir in the flour coated berries.
Scrape the batter into the buttered pan and smooth the top gently with the spatula. Using your fingertips, break the topping into pieces and scatter over the batter, gently pressing them into the batter. Place in the oven and bake 55 to 65 minutes, or until a knife inserted into the center of the cake comes out clean. The topping should be nicely browned. Cool before serving. You can serve this cake warm or at room temperature.