I printed this recipe for rhubarb squares several years ago, and it was an instant favourite that we've been making every year since when the rhubarb is up. It's tart, sweet, buttery perfection in every bite, with a rich custardy layer and bursts of juicy rhubarb. It's similar to a rhubarb custard pie, but much quicker to put together. The original recipe is here; I adapted it slightly and have modified it for maximum efficiency of time and fewest dirty dishes. It's one of those things that should only be made when company is coming, or else if you're like me, you'll have to fight yourself not to eat the entire batch.
Rhubarb Custard Squares
Makes an 8x8 pan, approximately 12 servings.
Preheat oven to 350.
On the stovetop in a medium pot, melt 1/2 cup butter. As it's melting, line an 8x8 pan with overlapping parchment paper, to make removal from the pan easy. Remove melted butter from heat and stir in 1/4 cup icing sugar and 1 cup flour. Spread evenly in pan with a wooden spoon or hands and bake for 15 minutes.
Meanwhile, combine in same pot (to save dishes!) 2 beaten eggs, 3/4 cup sugar, 1/4 cup flour, 1/4 tsp salt. Mix well, then fold in 2 cups diced rhubarb.
When the base comes out of the oven, pour the rhubarb mixture on top and bake for an additional 45 minutes, or until set and slightly golden. Cut into squares or bars and enjoy! You can double the recipe and use a 9x13 pan.