Rhubarb Squares Recipe (Rhubarb Bar Cookies)
Rhubarb squares recipe: a buttery shortbread-style base topped with a vanilla egg filling and chopped rhubarb. How to make: pre-bake the crust, pour over the rhubarb batter, bake, then cut into squares.
Ingredients
1. For the crust
2. For the filling
Step-by-Step Method
Preheat and prep the pan
Heat the oven to 350°F (175°C). Lightly grease a square baking pan or line it with parchment for easy lifting.
Make the crust mixture
Mix the flour and powdered sugar. Add cold butter and rub it in until you get fine, sandy crumbs.
Press and pre-bake
Press the crumbs firmly into an even layer in the pan. Bake 12–15 minutes, just until the edges start to turn lightly golden.
Whisk the filling
Stir together granulated sugar and 1/4 cup flour. Whisk in the eggs until smooth, then mix in the vanilla.
Fold in the rhubarb
Gently fold in the chopped rhubarb. If using frozen rhubarb, drain it well so the bars don’t get watery.
Bake until set
Pour the filling over the warm crust and level the top. Bake 28–35 minutes, until the center looks set and no longer jiggles.
Cool and slice
Let the pan cool completely on a rack. For cleaner cuts, chill for 30 minutes, then slice into squares.