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Cast Iron Blueberry-Cardamom Buttermilk Cake

By Nicole Konstantinakos

Published on March 3, 2025

Time

1¼ hours, plus 30 minutes cooling

Yield

Serves 8 to 12

Cast Iron Blueberry-Cardamom Buttermilk Cake

Ingredients

8 tablespoons unsalted butter 2½ cups (12½ ounces/354 grams) all-purpose flour 2½ teaspoons baking powder ½ teaspoon baking soda ¾ teaspoon ground cardamom ½ teaspoon table salt 1 cup (7 ounces/198 grams) plus 1 tablespoon sugar, divided2 large eggs ¾ cup buttermilk 2 teaspoons grated lemon zest 1 teaspoon vanilla extract 10 ounces (2 cups) blueberries

Before You Begin

Be sure the melted butter has cooled to room temperature before adding it to the sugar mixture in step 3. You can substitute frozen (unthawed) blueberries for the fresh (you may need to add up to 5 minutes to the baking time). For added flair, serve this cake drizzled with Tea Glaze.

Instructions

  1. Adjust oven rack to middle position and heat oven to 350 degrees. Melt butter in 10-inch cast-iron skillet over low heat; swirl over bottom and sides of skillet, then transfer to small bowl (do not scrape residual butter from skillet) and let cool to room temperature, about 10 minutes. 
  2. Whisk flour, baking powder, baking soda, cardamom, and salt together in medium bowl; set aside.
  3. Whisk 1 cup sugar and eggs in large bowl until mixture is pale and creamy, about 1 minute. Whisk in cooled butter until mixture is thick and creamy. Whisk in buttermilk, lemon zest, and vanilla until evenly combined. Using silicone spatula, fold flour mixture into buttermilk mixture until just combined (batter will be thick). Gently fold in blueberries.
  4. Transfer batter to skillet and smooth top. Sprinkle evenly with remaining 1 tablespoon sugar. Bake until cake is golden brown and toothpick inserted in center comes out clean, 40 to 45 minutes. Let cake cool in skillet on wire rack for 30 minutes. Serve warm or at room temperature. (Slices of fully cooled cake can be reheated briefly in microwave or skillet-toasted in butter, if desired.) 
Cast Iron Blueberry-Cardamom Buttermilk Cake
Photography by Steve Klise. Styling by Kendra Smith.

Cast Iron Blueberry-Cardamom Buttermilk Cake

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Time

1¼ hours, plus 30 minutes cooling

Yield

Serves 8 to 12

Ingredients

8 tablespoons unsalted butter
2½ cups (12½ ounces/354 grams) all-purpose flour
2½ teaspoons baking powder
½ teaspoon baking soda
¾ teaspoon ground cardamom
½ teaspoon table salt
1 cup (7 ounces/198 grams) plus 1 tablespoon sugar, divided
2 large eggs
¾ cup buttermilk
2 teaspoons grated lemon zest
1 teaspoon vanilla extract
10 ounces (2 cups) blueberries

Test Kitchen Techniques

Ingredients

8 tablespoons unsalted butter
2½ cups (12½ ounces/354 grams) all-purpose flour
2½ teaspoons baking powder
½ teaspoon baking soda
¾ teaspoon ground cardamom
½ teaspoon table salt
1 cup (7 ounces/198 grams) plus 1 tablespoon sugar, divided
2 large eggs
¾ cup buttermilk
2 teaspoons grated lemon zest
1 teaspoon vanilla extract
10 ounces (2 cups) blueberries

Test Kitchen Techniques

Ingredients

8 tablespoons unsalted butter
2½ cups (12½ ounces/354 grams) all-purpose flour
2½ teaspoons baking powder
½ teaspoon baking soda
¾ teaspoon ground cardamom
½ teaspoon table salt
1 cup (7 ounces/198 grams) plus 1 tablespoon sugar, divided
2 large eggs
¾ cup buttermilk
2 teaspoons grated lemon zest
1 teaspoon vanilla extract
10 ounces (2 cups) blueberries

Test Kitchen Techniques

Why This Recipe Works

For a fluffy, buttery, tangy-sweet cake that gives blueberries a chance to shine, we turned to the cast-iron skillet, which kept the cake warm and tender long after it came out of the oven. We added a trio of aromatics—cardamom, lemon zest, and vanilla—to complement but not compete with the berries. To avoid fussy mixing methods and appliances, we relied on the tried-and-true muffin mixing method, which yields a light and slightly loose crumb, perfect for showcasing berries. After melting butter in the skillet (which also served to grease the skillet), we whisked the dry ingredients together in a bowl. In a second bowl, we whisked the sugar and eggs until creamy (which both dissolved the sugar and incorporated air) and then added the remaining liquid ingredients. Finally, we folded the dry and liquid ingredients together (along with the berries), transferred the batter to the buttered skillet, and sprinkled the top with some sugar for a crackly crust. We served this cake right out of the skillet.

Before You Begin

Be sure the melted butter has cooled to room temperature before adding it to the sugar mixture in step 3. You can substitute frozen (unthawed) blueberries for the fresh (you may need to add up to 5 minutes to the baking time). For added flair, serve this cake drizzled with Tea Glaze.

Instructions

  1. Adjust oven rack to middle position and heat oven to 350 degrees. Melt butter in 10-inch cast-iron skillet over low heat; swirl over bottom and sides of skillet, then transfer to small bowl (do not scrape residual butter from skillet) and let cool to room temperature, about 10 minutes. 
  2. Whisk flour, baking powder, baking soda, cardamom, and salt together in medium bowl; set aside.
  3. Whisk 1 cup sugar and eggs in large bowl until mixture is pale and creamy, about 1 minute. Whisk in cooled butter until mixture is thick and creamy. Whisk in buttermilk, lemon zest, and vanilla until evenly combined. Using silicone spatula, fold flour mixture into buttermilk mixture until just combined (batter will be thick). Gently fold in blueberries.
  4. Transfer batter to skillet and smooth top. Sprinkle evenly with remaining 1 tablespoon sugar. Bake until cake is golden brown and toothpick inserted in center comes out clean, 40 to 45 minutes. Let cake cool in skillet on wire rack for 30 minutes. Serve warm or at room temperature. (Slices of fully cooled cake can be reheated briefly in microwave or skillet-toasted in butter, if desired.) 

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