I’m not done with rhubarb yet, are you? We’re about to hit “strawberry time” here, and I’m beyond excited for it, but I am not done with rhubarb. In fact, I am currently cultivating relationships with internet friends who are helping me grow my freezer stash. Rhubarb brings neighbors (and internet neighbors) together (special shout-out to Pauline!!!)
These Rhubarb-Lemon Bars are a springtime dream. They are rich and decadent with custard rising impossibly high on top of a shortbread cookie crust. But they are also homey and perfect for drawn-out evenings on the porch because rhubarb, lemon and buttery shortbread are just so comforting. Furthermore, the sprinkle of sliced rhubarb on top adds a puckering (and balancing) bit of tang, which will keep you reaching for seconds and thirds.
I’ve tried other rhubarb custard bar recipes, but they were always too sweet, too dry, or thad no tangy flavor. So, I rolled up my sleeves et viola! I did a little happy dance in my kitchen when I finally got these bars to my exacting tastes. They are similar to those luscious lemon bars you get at bakeries and coffee shops, but with the pucker, tang and depth that can only come from rhubarb. I hope that you like them as much as we do.
Notes
Note about Rhubarb Varieties:
Rhubarb stalks can be red, green, or speckled red and green. They’re just different varietials. I like to use red rhubarb for this recipe because it makes for such a beautifully colored bar. If I’m using stalks that are more speckled or have both red and green, I like to add a drop or two of food coloring to make the bars take on a more traditional rhubarb hue.
Note about Rhubarb Leaves:
The leaves are poisonous! If you buy rhubarb with it’s leaves, or harvest some yourself, simply cut the stalk below the juncture of the leaf and steam, and dispose of the leaves.
Key Ingredients
10 tbsp cold butter
1 1/4 cup all-purpose flour
~1 cup granulated white sugar
12 ounces rhubarb
3/4 medium sized lemon
4 eggs
Shortbread and Rhubarb-Lemon Custard – Recipe
Takes about 1 hour to make and then a few hours to cool. Makes 12-18 bars. Requires a food processor.
Ingredients
Shortbread Base
- 8 tablespoons cold unsalted butter
- 1 cup all-purpose flour
- 1/2 teaspoon Diamond brand kosher salt
- 1/3 cup granulated white sugar
Rhubarb-Lemon Custard
- 10 ounces rhubarb (about 2.5 cups)
- 3/4 cup granulated white sugar separated into 1/2 cup and 1/4 cup
- 3/4 medium sized lemon
- 1/4 teaspoon Diamond brand kosher salt
- 1/4 cup all-purpose flour
- 2 tablespoons cold butter cut into 1/4 inch pieces
- 4 eggs cold from the fridge
- 2 drops of red food coloring (optional)
- 2 ounces rhubarb (about 1/2 cup cut into 1/8 of an inch slices)
- 2 tablespoons powdered sugar (optional)
Shortbread Base
Step One
Preheat oven to 350 degrees. Line an 8×8 glass pyrex pan with parchment paper and lightly oil the paper.
Step Two
Combine flour, salt, and sugar in the bowl of a food processor. Pulse to combine. Cut butter into 1 tablespoon pieces and add on top of dry ingredients. Pulse with the mixer until a powdery crumb forms. Press the short bread dough into the greased 8×8 pan, then bake for 16-22 minutes or until the short bread looks cooked and takes on a light golden color. Remove from oven and set aside.
Rhubarb-Lemon Custard
Step One
While the shortbread cooks, chop your rhubarb into 1/2 inch pieces and add to a small saucepan. Squeeze the juice of half a lemon over the rhubarb (set other half of the lemon aside) and add 1/2 cup sugar. cook down the rhubarb over medium low heat until it softens and starts to break down (about 10-15 minutes). Set rhubarb aside to cool for 10 minutes.
Step Two
Cut your other half of a lemon in half again. Remove the nippled end from your lemon and discard it. Your lemon wedge should be about 1-2 inches thick, but then cut the wedge into 1/4 inch pieces slices so you can remove any seeds. Add that sliced lemon to your food processor bowl. Pour 1/4 cup of sugar in with the lemon slices. Run the food processor until the lemon is broken down with the sugar. Then add the rhubarb, flour, and salt and process until you have a thick purée. Lastly, add the 4 eggs and the 2 tablespoons of chopped butter.
Step Three
Pour the custard mixture on top of the shortbread and then sprinkle the finely sliced rhubarb on top of the custard. Bake for 20-25 minutes until the custard sets. It should just start taking on a little light coloring around the edges. Allow custard to cool before cutting and toping with optional powdered sugar.
Rhubarb-Lemon bars are best within the first 48 hours but will keep for four days covered and stored in the fridge.