Rhubarb-Lime Icebox Pie
Chef and cookbook author Amy Thielen’s recipe for a tangy rhubarb custard pie.
So many people in the American Midwest grow rhubarb in their yards that many of the area’s local grocery stores don’t even bother to sell it in the spring. Come May, everywhere you turn there’s rhubarb crisp, or rhubarb pie, or stewed rhubarb over ice cream. Following the local tradition of adding rhubarb to every reasonable thing during the season, here’s a pie that looks and tastes like a pink Key lime pie.
The creamy filling gets its requisite tartness from a quickly stewed pot of fuschia rhubarb, to which you add the elements of a classic Key lime custard: egg yolks and condensed milk. The color depends on the rhubarb you use—the redder the stalk, the pinker the pie. (If you like, add a drop of red food coloring to a filling made with greenish rhubarb.)
And take a cue from those retro diners famous for their icebox pies: Whip the cream just until soft and billowy and sculpt it into a dramatic pompadour on top.
- 9-Inch Pie Plate
- Large Bowl
- Medium Pot
- Immersion Blender or Food Processor or Blender
- Large Baking Sheet
- Plastic Wrap
- Stand Mixer Fitted with the Whip or Large Bowl, using a Balloon Whisk
For the shortbread crust
- Nonstick spray or canola oil, for greasing
- 1½ cups finely ground shortbread crumbs (from store bought or homemade shortbread)
- 5 Tbsp. sugar
- ½ tsp. ground ginger
- 3 Tbsp. salted butter, melted
For the filling and topping
- 2½ cups (10 ounces) diced rhubarb
- ½ cup plus 2 Tbsp. sugar, divided
- ⅓ cup fresh lime juice (from about 4 limes)
- One 14-ounce can sweetened condensed milk
- 4 large egg yolks
- 1½ cups heavy cream
- ½ tsp. vanilla extract
- Make the shortbread crust: Preheat the oven (with one of its racks positioned in the center) to 350°F. Spray a 9-inch pie plate with nonstick spray (or rub it with a little canola oil) and set it aside.
- To a large bowl, add the shortbread crumbs, sugar, ginger, and melted butter and mix with a fork to combine. Pour the crumb mixture into the prepared pie plate and press it into an even layer along the bottom and all the way up the sides, pinching slightly to form a little lip above the rim of the pie plate. Transfer to the oven and bake until the crust is fragrant and light brown, 8–10 minutes.
- Remove the crust from the oven and reduce the oven temperature to 325°F.
- Make the filling: To a medium pot, add the rhubarb, ½ cup of the remaining sugar, and the lime juice and stir well to combine. Set over medium-low heat and bring to a simmer. Cook, uncovered, stirring occasionally, until the rhubarb is beginning to break down, 10–12 minutes. Remove from the heat and set aside to cool slightly, then blend the stewed rhubarb mixture with an immersion blender (or, alternatively, transfer it to a food processor or blender and process) until smooth. Add the condensed milk, then continue blending to combine. Finally, add the egg yolks, and continue blending until smooth.
- Pour the filling into the reserved pie shell, place the pie on a large baking sheet, transfer to the oven, and bake until the custard is completely set and no longer jiggling at the center, 25–30 minutes. Set the pie aside to cool to room temperature, then transfer to the fridge and chill completely, at least 3 hours or up to 2 days. (If refrigerating for longer than a few hours, cover the surface of the pie loosely with plastic wrap.)
- Finish the pie: To the bowl of a stand mixer fitted with the whip (or to a large bowl, using a balloon whisk), add the cream, the remaining 2 tablespoons sugar, and the vanilla and whip until lofty and just beginning to form stiff peaks. Retrieve and uncover the chilled pie and scoop and spread the whipped cream over the top in an even layer. Cut into wedges and serve. Keep any leftover pie loosely covered in the fridge.