Makes 24 2-inch squares
This is a great treat to make and enjoy, and a fun way to introduce folks to the joys of rhubarb! The crust and streusel topping work great with other seasonal fruit all year long.
1 cup plus 5 Tbsp unsalted butter,
melted and cooled to just warm
1 ½ cups sugar
¾ tsp salt
2 large egg yolks
3 cups plus 3 Tbsp all-purpose flour
2 ½ cups hulled/diced strawberries
2 ¼ cups diced rhubarb, sliced ¼ inch
1 Tbsp plus 1 tsp fresh lemon juice
¼ cup water
1 Tbsp plus 1 tsp cornstarch
In medium saucepan, bring strawberries, rhubarb, ½ cup sugar, lemon juice and 2 Tbsp water to a boil over high heat. Mix 2 Tbsp. water to cornstarch to make a slurry and add to fruit. Reduce heat to low-medium and continue to boil until fruit is brokendown and syrupy-thick, 30 to 45 minutes.
Remove pan from heat and let mixture cool 5 to 10 minutes – syrup will continue to thicken as it cools.
Line a 13×9-inch baking pan with foil, letting ends create overhanging edge for easy removal. In medium bowl, stir together butter, ¾ cup of the sugar and salt. Whisk in egg yolks. Stir in flour to make stiff dough.
Transfer about 2 cups of dough to prepared pan, press mixture evenly into the bottom. Prick dough all over with a fork. Refrigerate pan for 30 minutes (or freeze 5-7 minutes), until dough is firm.
Position one oven rack near center and another near top. Heat oven to 325°. Bake dough until crust begins to set but doesn’t brown at all on edges (center won’t be firm yet), about 20 minutes. While crust bakes, prepare streusel topping.
Using your fingers, combine remaining ¼ cup sugar with reserved dough until crumbly. Mixture should hold together when pressed, but readily break into smaller pieces. Spread filling evenly over hot crust. Scatter streusel over filling – don’t crumble too much or filling will be sandy.
Increase oven temperature to 350° and bake bars near top of oven until streusel is golden and set, about 25 minutes.
Place pan on metal rack to cool until crust is completely firm, at least 1 hour. When bottom of pan is cool, carefully lift bars from pan using foil sides and transfer to cutting board.
Separate foil from bars by sliding spatula between them. Cut bars into 2 ¼ inch squares.