Rhubarb Custard Cake
This is an interesting cake, as it isn’t particularly cakey, instead it bakes up to be a firmish custard that is sliceable and made all the more tasty with a scoop of ice cream. I’ve posted a fair number of rhubarb desserts here not only because I love tangy desserts but also because I’m lucky enough to have a close friend who has a large rhubarb patch and FedEx me rhubarb each year for the past couple of years. So of course when we have them over I have to make a rhubarb dessert. I didn’t have the time to make pie pastry so thought I’d try this Bon Appetite recipe instead.
Now my rhubarb is frozen and was sliced to 1.5-2” lengths. This recipe calls for much longer lengths but this worked out none the less. I allowed my rhubarb to defrost in the fridge overnight and because the rhubarb needs to stay at the top of the cake, I discarded the rhubarb water that came off the defrosted rhubarb but didn’t squeeze the rhubarb to remove anymore.
For 9” springform pan
4 Tbsp. melted unsalted butter, cooled, plus more room-temperature for pan
1 cup all-purpose flour, plus more for pan
¾ tsp. baking powder
½ tsp. kosher salt
2 large eggs
1 large egg yolk
1½ cups sugar, plus more for sprinkling
¼ cup sour cream
2 Tbsp. dark rum
2 tsp. finely grated lemon zest
13 oz. rhubarb stalks, halved lengthwise if thick
Preheat oven to 350°. Butter and flour pan. Whisk baking powder, salt, and 1 cup all-purpose flour in a medium bowl. Whisk eggs, egg yolk, and 1½ cups sugar in a large bowl until very pale and thick, about 1 minute. Whisk melted butter, sour cream, rum, and lemon zest in a small bowl. Whisk butter mixture into egg mixture just to combine. Add dry ingredients and fold in until batter is smooth; scrape into prepared pan. Chill 10 minutes to let batter set.
Arrange rhubarb over batter however you like, trimming as needed. Don’t press fruit into batter—just place over top and let it rest on the surface. Sprinkle with more sugar and bake until cake is golden on top and browned around the sides, 45–55 minutes. Transfer pan to a wire rack and let cake cool in pan 10 minutes. Slide a knife around sides of cake to loosen and unmold. Slide directly onto rack and let cool completely.
Do Ahead: Cake can be baked 1 day ahead. Store tightly wrapped at room temperature.