Strawberry-Rhubarb Shortbread Bars

Let's Cook

1. Step 1.

   Preheat the oven to 350°F. Line a 9-inch square baking pan with parchment paper, leaving a 2-inch overhang on two opposite sides.

2. Step 2.

   In a medium saucepan, combine 1½ cups sliced rhubarb, 1 cup sliced strawberries, ½ cup granulated sugar, and ¼ cup water. Bring to a boil over medium-high heat, then cook until the fruit is softened and beginning to break down, 2 to 4 minutes. Remove from heat and let cool completely.

3. Step 3.

   While the fruit cools, in a food processor, pulse 3 tablespoons confectioners' sugar, ½ teaspoon kosher salt, and 1 cup all-purpose flour to combine, 4 to 5 times. Add ½ cup (1 stick) cold unsalted butter cut into pieces and pulse until a coarse meal forms, 10 to 12 times. Press the mixture firmly into the bottom of the prepared pan. Bake until golden brown around the edges, 16 to 20 minutes. Let the crust cool completely in the pan.

4. Step 4.

   Wipe out the food processor. Add the cooled rhubarb mixture and puree until very smooth, about 1 minute. Add 2 large eggs, 2 large egg yolks, 1 tablespoon fresh lemon zest, and the remaining ⅓ cup granulated sugar; process until smooth, 15 to 20 seconds. Add 5 drops red food coloring and the remaining 3 tablespoons all-purpose flour; pulse just until smooth. Pour the filling over the cooled crust.

5. Step 5.

   Bake until the filling is set, 25 to 30 minutes. Let cool completely in the pan, then refrigerate for at least 2 hours or up to a day. When ready to serve, use the parchment overhangs to lift the bars onto a cutting board and cut into 16 squares. Garnish with additional sliced strawberries.