Rhubarb Shortbread Bars are a dream come true! A thick and buttery shortbread crust, topped with a layer of simple rhubarb filling, and topped with even more glorious shortbread. There is a secret ingredient in this recipe that makes these rhubarb bars bright ruby red, and it’s not food coloring. It works like a charm!

rhubarb bars

Shortbread Pastry

Charlotte is sitting next to me at the table doing her math homework. She was in the middle of a larger problem, talking out loud to herself and said, “13 minus 8 is…” and before she figured it out I volunteered, “Five.” She was completely flabbergasted. “REALLY??”  Yes, really. Then I saw her discreetly count it out to make sure. “Huh. You’re right,” she said.

rhubarb bars with shortbread crust

I don’t get no respect around here. Since we started this whole “distance learning” business, Charlotte has figured out that I am not the adult in the house to come to when there is a math problem to be solved. Now apparently she thinks I don’t even know how to subtract. I may not be a rocket scientist but SHEESH Charlotte!! Give your old mom a break!

rhubarb bars with shortbread crust

In other news, it’s rhubarb season!!! If this is not triple-exclamation-point worthy info for you, then you are missing out. Eric’s parents are in town for a visit, and I just asked them if they have any old family jokes about rhubarb that I could talk about here on the blog. Kris, my mother-in-law said, “I don’t know Karen, rhubarb is a subject we don’t joke about in our family. We take rhubarb pretty seriously around here.”

rhubarb crumble bars

Ha! We mean business when it comes to rhubarb. Before marrying into Eric’s family, I had never even heard of it, and now I’m duly obsessed just like everyone else. Eric’s dad just told me that when he was a kid he and his buddies would steal rhubarb stalks from the neighbor’s yard and eat them raw. No thank you! I like my rhubarb with sugar, in a pie preferably! Or these rhubarb shortbread bars!

rhubarb bars recipe

Kris has been making her grandmother Prudy’s Rhubarb Dream Bars for years and years, and I will get around to posting them someday (they are very similar to these Rhubarb Meringue Layers, just without the meringue), but with this crop of rhubarb I wanted to try out some simple shortbread bars. I’ve been obsessed with shortbread bars lately; see evidence in the Cherry version, apple version, cranberry version… there is just something amazing about fresh fruit and buttery sugary shortbread. It’s my favorite!

how to prepare rhubarb

The reason I love shortbread bars so much is because they are not too sweet. Shortbread compliments the natural tartness of the rhubarb so well. Sure there is some sugar in there, but we are not topping our rhubarb bars with a crumble made primarily from sugar; instead it’s extra buttery crust going on top. Just like a pie!! I should have called these Rhubarb Pie Bars!

How to make Rhubarb Dream Bars

These rhubarb bars are suuuper easy to put together!

How to make shortbread crust

First put together your shortbread crust. It’s just butter, sugar, vanilla, flour and salt. Back to the basics, yo. This stuff is so simple and so good. Bake it up and set aside to cool.

preparing rhubarb stalks and chopped rhubarb

Then chop up your rhubarb. I like to slice the rhubarb lengthwise and then chop it.

How to prepare rhubarb so that it’s bright red

And here’s where the magic happens.

grenadine syrup for rhubarb bars

Grenadine syrup! This is a super easy hack for getting your rhubarb to bake up bright red instead of that ugly green-brown color it can turn to in the oven. It makes it so pretty! We are soaking the rhubarb in grenadine for an hour or two, then draining.

If you don’t have grenadine or can’t find it (it was at my local store on the liquor aisle, next to the vodka) you can skip this step. Add a couple extra tablespoons of sugar to the rhubarb filling and you will be good to go.

rhubarb crumble bars

Look at this bright red rhubarb! No strawberries necessary. I have nothing against strawberries, but I just love rhubarb all by itself and don’t want to have to depend on strawberries for consistent color. Why is rhubarb such a weird color?? It is like the only dessert fruit I can think of that bakes ugly. Grenadine and rhubarb for the win! Make these soon, you won’t regret it!

More rhubarb recipes you are going to love!

Rhubarb Custard Pie << this will forever and always be my favorite pie!

Rhubarb Meringue Layers << My other favorite Rhubarb dessert! shortbread crust + meringue? Forgetaboutit

Strawberry Rhubarb Sauce << perfect for pancakes, or spooning directly into your mouth :)

Rhubarb Cream Cheese Muffins << these are so tasty! Cream cheese and rhubarb ftw.

Strawberry Rhubarb Italian Sodas << the only thing better than eating rhubarb is drinking it!

Mom’s Rhubarb Crisp from The Taylor House

Strawberry Rhubarb Crisp from Recipe Rebel

Rhubarb Curd from Vikalinka

More shortbread bar recipes you are going to die for!

I’m a little obsessed with shortbread bars you guys. They are just the best! I will make a version of shortbread bars with every single fruit in existence someday before I die. There, bucket list item, proclaimed!!

Apple Pie Bars << the BEST.

Easy Homemade Cherry Pie Bars << no, these are the best.

Cranberry Shortbread Bars << These are amazing at Christmas time!

The Best Lemon Bars << If you are a lemon lover, these are for you!

Gooey Pecan Pie Bars with Toffee << Let’s not limit ourselves to the holidays here.

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rhubarb bars
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Rhubarb Shortbread Bars

Rhubarb Shortbread Bars are a dream come true! A thick and buttery shortbread crust, topped with a layer of simple rhubarb filling, and topped with even more glorious shortbread. There is a secret ingredient in this recipe that makes these rhubarb bars bright ruby red, and it's not food coloring. It works like a charm!


For the crust/topping

  • 1 cup butter, softened (2 sticks)
  • 3/4 cup granulated sugar
  • 1 & 1/2 teaspoons vanilla
  • 2 cups all-purpose flour, spooned and leveled
  • 3/4 teaspoon kosher salt

For the rhubarb filling

  • 3 cups rhubarb, chopped (about 5 stalks)
  • 1/2 cup grenadine syrup, to be drained eventually*
  • 3/4 cup sugar
  • 1/4 cup all purpose flour
  • 1 tablespoon lemon juice, optional
  • 1 teaspoon lemon zest, optional

For the glaze

  • 1 cup powdered sugar
  • 2-3 teaspoons milk, more or less to taste
  • 1/2 teaspoon vanilla
  • pinch salt


  • Begin by prepping the rhubarb: chop the rhubarb into bite size pieces. I like to split each stalk at least in half lengthwise (if not thirds) so that you don't get any huge chunks. After slicing, chop into 1/2 to 1 inch pieces.
  • Add all the rhubarb to a bowl, along with 1/2 cup grenadine syrup. Stir it all together so that the rhubarb is coated. Let sit for 1-2 hours on the counter stirring occasionally, or even overnight (put it in the fridge, covered, if you go overnight.) This is to get the rhubarb a nice bright red color. It is not a necessary step but it sure is pretty!* When you are ready to make the rhubarb bars, drain the rhubarb in a colander.
  • While the rhubarb soaks, prepare the shortbread crust. Preheat the oven to 375 degrees F.
  • Line an 8x8 or 9x9 inch square pan with parchment paper, or spray with nonstick spray. Set aside.
  • In a large bowl or stand mixer, add 1 cup (2 sticks) softened butter. Beat until smooth and creamy, making sure to scrape the sides and bottom of the bowl.
  • Add 3/4 cup granulated sugar and beat again for at least 1-2 minutes, stopping to scrape the sides and bottom, until the mixture is light and fluffy.
  • Add 1 and 1/2 teaspoons vanilla extract and beat.
  • Add 2 cups of flour, spooned and leveled, and 3/4 teaspoon kosher salt.
  • Beat in the flour and salt until the mixture has come together and has formed a ball. Scrape sides as necessary. Do not over mix; beat just until the flour is combined and then no more (otherwise your shortbread will be tough).
  • Divide the dough into two, one with a little more than half the dough. (Cover the smaller piece of dough and put it in the fridge.)
  • Press a little more than half of the dough into the prepared square pan. Getting your hands a little damp can be helpful. I like to leave the edges raised a half inch or so, so that you have a bit of crust on the edge pieces, but pressing it all flat will work too. If you have time, chill the dough for a few minutes, 10-20 minutes is best. Cold dough going into a hot oven makes for very tender shortbread.
  • Bake the crust at 375 for about 15 minutes, or until light brown on the edges. My shortbread puffed up in the middle even though I had made a raised crust, so I gently pressed the center back down with the back of a spoon, when it was very hot from the oven still.
  • Set the crust aside and let cool for a few minutes.
  • Leave the oven on but lower the temperature to 350 degrees F.
  • Meanwhile, prepare the rhubarb filling: drain the rhubarb in a colander or strainer. Add your red rhubarb to a medium bowl.
  • Stir in 3/4 cup sugar (add a couple extra tablespoons if you skipped the grenadine soak*).
  • Add 1/4 cup all purpose flour and stir.
  • At this point you can add 1 tablespoon lemon juice and 1 teaspoon zest, but it is optional. It brightens up the flavor of the rhubarb, but you can definitely taste the lemon. Feel free to add just the juice and skip the zest for a milder hint of lemon. If you are a rhubarb purist, skip the lemon entirely.
  • Pour the rhubarb filling over the baked crust.
  • Use you fingers to break off medium pieces of shortbread from your stash in the fridge. Check the photos to see the size we're talking. I like big ol chunks. You don't have to cover the rhubarb entirely.
  • Bake the rhubarb bars in the oven at 350 for about 45-50 minutes. The bars are done when the shortbread on top is golden in several spots across the top. A fork should also slide easily into a piece of rhubarb; it should be completely tender.
  • Let the bars cool completely. I stuck mine in the freezer to speed this up.
  • If you would like to top with a vanilla glaze, in a medium bowl combine 1 cup powdered sugar with 2 teaspoons milk, 1/2 teaspoon vanilla, and a pinch of salt. Whisk until smooth. Drizzle over the top of the cooled bars and let the glaze set up for 20-30 minutes before slicing and serving.


*If you don't soak the rhubarb in grenadine (the recipe will still work fine), add 2 extra tablespoons sugar to the rhubarb filling (3/4 cup plus 2 tablespoons.) 


Serving: 1 g, Calories: 535 kcal, Carbohydrates: 85 g, Protein: 4 g, Fat: 21 g, Saturated Fat: 13 g, Polyunsaturated Fat: 1 g, Monounsaturated Fat: 5 g, Trans Fat: 1 g, Cholesterol: 54 mg, Sodium: 386 mg, Potassium: 167 mg, Fiber: 2 g, Sugar: 55 g, Vitamin A: 674 IU, Vitamin C: 4 mg, Calcium: 49 mg, Iron: 2 mg