I am all about using in-season produce, especially if it’s from my own backyard! We are totally Team Rhubarb at my house and I have a crazy, high-producing rhubarb plant which sends up stalks from early May to late September. This 1970s throwback recipe is my go-to for using up this tart vegetable. Par bake the shortbread-style crust to be able to stand up to the thick, delicious rhubarb filling. A crowd-pleaser recipe that doesn’t even taste gluten free.
2 cups sugar, divided
1 cup butter, at room temperature
1 cup water
2 Tbl cornstarch
1 tsp vanilla
5 cups diced rhubarb
Preheat oven to 350 degrees. Line a 9×13 pan with parchment hanging off the long sides to form handles (I use a metal pan with straight corners, but have also used a glass baking dish without parchment). Lightly spray the parchment and the non-lined short sides of your baking pan to ensure everything comes out in one piece. In the bowl of a stand mixer blend together flour, 1 cup of sugar, and butter. Flour mixture should be combined well and resemble the texture of peas. Reserve one cup of flour mixture for topping. Spread remaining flour mixture in the baking pan and compact to form a thick crust. Bake crust for 10 minutes then cool slightly. While crust is baking, in a small sauce pan combine water, remaining 1 cup of sugar, and cornstarch. Heat until thick and bubbling, whisking contantly. Remove from heat and let cool. Add vanilla and stir to combine.
On top of cooled crust spread the diced rhubarb into a thick, even layer. Don’t be convinced you need to use more than 5 cups of rhubarb because it will make the crust wet and runny. Dribble cooked sauce over the top of the rhubarb and add the 1 cup of crumbs for topping.
Bake 45-55 minutes and let cool completely in the pan. Run the edge of a knife around the short edges of the pan to loosen. Gently pull on parchment to release bars. Sometimes it helps to refrigerate the pan first. Remove parchment and cut into 18 bars. Refrigerate leftovers.