Gail Simmons is such a glamorous presence on “Top Chef” that it’s easy to forget she’s first and foremost a great cook. She’s also a fellow Canadian so I took a great deal of heat from Andrew for not knowing what a Bumbleberry was. I’d never heard the expression. But Ms. Simmons assured her readers in a recent edition of Food & Wine magazine that bumbleberries are a real thing. A mixture of in-season berries—never less than three and most commonly blueberries, blackberries and raspberries–make up a bumbleberry. These are then tossed together and cooked into a pie, jam or, in this case, an upside-down cake. I am going to forgive myself. I am, after all, a Québecois, Ms. Simmons an Ontarian. Neighbors though our provinces may be, our culinary traditions are quite different. Mine are French, Ontario’s, until recently, British. It’s a shame that the bumbleberries never made their way across the provincial border. Because this is one terrific ingredient. And in Ms. Simmons’ hands, one really great cake.
There are the berries of course, somehow even juicier when brought together. And there’s a lemon-y flavor
too all a matter of adding a generous spoonful of lemon zest. The buttermilk makes the cake moist and adds just a hint of tartness. This cake is an ode to summer which makes it just about a perfect way to celebrate, if we must, Labor Day weekend.
If you’ve ever used a cast iron skillet to make corn bread, you’ll be right at home here. What you’ll end up with is a golden vanilla 
cake topped with a blanket of ‘bumbleberries’—a beautiful mass of magenta atop the cake. Andrew gilded this lily with dollops of Crème Fraiche, whipped up at the last minute. It’s a delicious foil to the sweetness of the berries.
One note: Ms. Simmons offers one word of encouragement writing “Don’t be discouraged if the cake batter seems thick or difficult to spread over the berry mixture in the skillet. It will loosen and spread out evenly while baking.” Here is the recipe:
Bumbleberry Buttermilk Upside Down Cake
A luscious berry-rich cake with a lemon-y moistness.
Ingredients
- 3/4 cup unsalted butter (6 ounces), cubed, at room temperature, divided
- 1 tablespoon fresh lemon juice
- 1 1/2 cups granulated sugar, divided
- 1 teaspoon kosher salt, divided
- 2 cups mixed fresh berries (such as blueberries, raspberries, and blackberries, blackberries halved if large)
- 4 teaspoons lemon zest, divided
- 2 large eggs
- 1 1/2 teaspoons vanilla extract
- 1 1/3 cups all-purpose flour (about 5 3/4 ounces)
- 1 1/2 teaspoons baking powder
- 1/2 teaspoon baking soda
- 1/2 cup whole buttermilk
- Powdered sugar, for dusting
- Whipped Crème Fraiche, for serving (optional)
Directions
- Step 1 Preheat oven to 350°F. Melt 1/4 cup butter in a 10-inch cast-iron skillet over medium. Stir in lemon juice, 1/2 cup sugar, and 1/2 teaspoon salt
- Step 2 Cook, stirring, until mixture is bubbly and sugar is mostly dissolved, about 2 minutes. Remove skillet from heat.
- Step 3 Toss berries and 2 teaspoons lemon zest in a medium bowl until combined. Arrange berries evenly over sugar mixture in skillet. (If using halved large blackberries, place cut sides up.) Set aside.
- Step 4 Place remaining 1/2 cup butter and remaining 1 cup sugar in bowl of a stand mixer fitted with the paddle attachment. Beat on high speed until mixture is light and fluffy, about 3 to 5 minutes. Reduce speed to medium. Add eggs, 1 at a time, beating well after each addition. Beat in vanilla extract and remaining 2 teaspoons lemon zest.
- Step 5 Whisk together flour, baking powder, baking soda, and remaining 1/2 teaspoon salt in a medium bowl. Add flour mixture one-third at a time to butter mixture alternately with buttermilk, beginning and ending with flour mixture, beating on low speed until just combined after each addition. Spoon batter over berry mixture in skillet, and spread gently over berries.
- Step 6 Place skillet on a rimmed baking sheet. Bake in preheated oven until cake is lightly browned and a wooden pick inserted in center of cake comes out clean, 40 to 45 minutes. Remove from oven, and let cool 30 minutes.
- Step 7 Run a butter knife around edge of cake
- Step 8 Place skillet over low to just warm bottom, about 2 minutes. Remove skillet from heat
- Step 9 Carefully invert cake onto a large plate. Serve cake lightly dusted with powdered sugar and, if desired, with whipped Creme Fraiche on the side.