The swirl of rhubarb is punched up with a subtle touch of tart hibiscus tea. See the note at the bottom of the recipe for more information about the hibiscus tea. The unusual method of baking the cake from a cold oven keeps the crumb tight and moist. If you want the filling to be a little more ruby red, try adding a 1/2 teaspoon of red food coloring to the filling. But that’s strictly cosmetic and is your call.
Prep time: PT20M
Cook time: PT90M
Total time: PT110M
Ingredients
3 Hibiscus tea bags (see note at the bottom of the recipe)
2 cups 1/2-inch chopped rhubarb (8 ounces or 4 to 5 fat stalks/8-10 skinny stalks)
1/2 cup white granulated sugar (100 g)
3 tablespoons cornstarch
4 ounces cream cheese at room temperature (1/2 brick)
12 tablespoon unsalted butter at room temperature (1 1/2 sticks, 6 ounces or 170 g)
1 1/2 cups white granulated sugar (300 g)
1 teaspoon baking powder
1 teaspoon baking soda
1/2 teaspoon kosher salt
Zest of 2 Meyer lemons
3 large eggs
2 cups buttermilk
Juice from 2 Meyer lemons
3 1/4 cups all-purpose flour (455 g)
Powdered sugar
Steps
Make the rhubarb swirl by first measuring out 1/2 cup of boiling water and placing the hibiscus tea bags into the hot water. Set aside for 15 to 20 minutes or until the water cools to room temperature. Meanwhile, place the rhubarb in a small saucepan with the sugar. Cook on medium heat, until the rhubarb softens and starts to fall apart about 5 to 7 minutes. Remove from heat and scrape into the bowl of a stand mixer fitted with a paddle attachment.
Once the hibiscus tea has cooled to room temperature, remove the tea bags and gently squeeze them to get as much liquid as possible out of them. Measure out 1/4 cup of the concentrated tea and stir in the cornstarch. Pour into the bowl with the cooked rhubarb. Add the cream cheese. Mix until blended. Pour the batter into a small bowl and set aside.
Prep the bundt pan by spraying it with cooking oil, making sure to get all the nooks and crannies. Dust with all-purpose flour and place on a rimmed baking sheet or pizza pan.
Make the cake batter by placing the butter, sugar, baking powder, baking soda, salt and lemon zest in the same stand mixer bowl (no need to clean it). Mix on medium speed until the butter is creamy and clings to the side of the bowl. Mix in the eggs, one a time, waiting for each egg to incorporate before adding the next one. Scrape down the sides of the bowl.
Combine the buttermilk and lemon juice together. Mix in 1 cup of the flour, then 1 cup of the buttermilk liquid, scraping down the sides of the bowl between additions. Repeat again with the flour and liquid, then end with the remaining 1 1/4 cup of flour.
Spoon 1/3 of the batter into the bottom of the pan. Make a “moat” in the middle of the batter, then spoon half the rhubarb batter into it, trying to keep as much rhubarb away from the edge of the pan. Repeat with the cake batter and rhubarb again, then finish with the remaining cake batter.
Place cake in the cold oven, then turn the oven on to 300°F. Let the cake bake for 80 to 90 minutes or until a toothpick inserted into the middle of the cake comes out clean (or if you have an instant read thermometer, when the cake reads 210°F). Let the cake cool in the pan for 20 minutes, then invert the still warm pan onto a wire rack and release the cake from the pan. Continue to let the cake cool to room temperature then move the cake to a serving plate. Dust with powdered sugar immediately before serving.
