If you love rhubarb and date bars/matrimonial squares you'll LOVE these Rhubarb Squares. And even if you're not a rhubarb lover, you won't be able to get enough of these squares- they are totally addictive. Spring is here and that means rhubarb reason!
Although I freeze fresh rhubarb and use it all year round, I can never seem to get enough and can't wait for it to come up in the spring. These Rhubarb Oatmeal bars were inspired by my date squares, which also make a great dessert after a lovely spring meal. Try it with my Spring Salad with Fiddleheads & Blackberry Vinaigrette. This is the best rhubarb dessert!
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These Rhubarb Squares, also known as Rhubarb Crumble Bars or Rhubarb Matrimonial Bars have a delicious rhubarb compote filling that's the perfect balance of tart and sweet, nestled between a scrumptious oatmeal base and topping. They are ideal for using up an abundance of rhubarb and make a perfect spring dessert or snack!
l only started growing my own rhubarb a couple of years ago so I get really excited when it starts to come in!
And I can't wait to think of what to bake next. So far, I only have a few rhubarb recipes: my No Bake Light Red & White Chocolate Rhubarb Cheesecake, Rhubarb Compote Recipe, Sticky Rhubarb Pudding, my No Bake Rhubarb Dessert and my Healthy Rhubarb Muffins (Weight Watchers Friendly) but I'm working on more!
🥘Ingredients
For this rhubarb oatmeal bar recipe, you'll need:
- all-purpose flour
- brown sugar
- quick rolled oats
- butter
- baking soda
- rhubarb
- lemon zest
- white granulated sugar
- cornstarch
- red food coloring (optional) (affiliate link)
*See recipe card for quantities.
🔪Instructions
How to make rhubarb squares
Although they are easy to make, there are several steps:
- Filling: Cut rhubarb into ½ inch pieces. In a medium saucepan, combine rhubarb with 1 ½ cup sugar and lemon zest, on stovetop on medium heat. Cook until tender, (about 15 minutes).
- Combine ½ cup sugar and with cornstarch, stir into cooked rhubarb
- Continue cooking for an additional 10 minutes (approximately) until rhubarb is completely broken down (as shown). Cool.
- To achieve a pink color, add food coloring, if desired.
- Base & Topping: Preheat oven to 375 degrees F/ 190 degrees C. Spray a 9X13 pan with non-stick cooking spray. In a medium bowl, stir flour, baking soda, brown sugar and oats together. Cut in cold butter into dry ingredients using a pastry cutter (or see my top tip below for an easier way to cut in butter)
- Assembly: Pat ½ the mixture into prepared baking pan.
- Then add rhubarb mixture on the bottom crust. Spread evenly with a rubber spatula.
- Add remaining flour/oat crumb topping mixture over rhubarb layer.
- Bake in preheated oven for 35 - 40 minutes or until lightly browned on top. Cool and cut into squares. Garnish with whipped cream and cinnamon sprinkles, if desired.
Hint: It's important to wait until rhubarb squares are completely cooled before cutting, otherwise they will fall apart. You can put them in the freezer to speed up the process!
📖Variations & Substitutions
- Lemon zest - you can use 2 teaspoons of lemon juice instead or use orange zest
- Color - add a little food coloring to your rhubarb compote so it looks more appetizing (red and not brown). I like to use Americolor super red (affiliate link) so I use less food coloring.
👪 Serving Size
This rhubarb bars recipe makes 16 square servings. However, you can cut them in half (into triangles) and get 32 servings. You can also half, double or triple the recipe by clicking on the blue serving number and selecting the number of servings you'd like. The ingredient quantities will automatically adjust. If you half the recipe, you'll need a 9-inch pan (square) and if you double it, you'll need an additional 9X13 pan.
🍽Equipment
For these rhubarb squares you need a 9X13 baking pan (affiliate link). I like to use a pan that comes with lid so once it cools, I can pop it into the fridge in the same container.
🌡️Storage
Store these rhubarb oatmeal bars in the fridge in a airtight container for up to 4 days (if they last that long!) and freeze them for up to 3 months in a sealed container.
💭Top tip
Keep your butter frozen (or at least very cold) and grate it into recipe. It's easier and less messy!
❔ Frequently Asked Questions
To freeze rhubarb, cut off bottom of rhubarb stalks, wash and chop stalks into approximately ½ inch pieces. Add 3-4 cups to a large Ziplock freezer bag. Before you using it in a recipe, thaw it completely, drain off excess water and measure it at that point.
Do you have to peel rhubarb before you cook it?
There is no need to peel rhubarb before you cook it. Rhubarb will break down when cooked, so it's no longer stringy.
If you are looking for a rhubarb square recipe or simply a way to use up your rhubarb harvest, you'll love this one!
And be sure to try my No Bake Rhubarb Cream Cheese Bars!
MORE RECIPES! To see full recipe menu, click HERE!
📋 Rhubarb Square Recipe
Ingredients
Filling
- 4 cups rhubarb
- 2 teaspoon lemon zest
- 2 cups sugar
- 2 ¾ tablespoon cornstarch
- Drop red food colouring optional
Base & Topping
- 1 ½ cups all-purpose flour
- 1 cup brown sugar
- 1 ¾ cups rolled oats
- 1 cup cold unsalted butter
- ¼ teaspoon baking soda
- ½ teaspoon cinnamon
Instructions
Filling
- Cut rhubarb into ½ inch pieces. In a medium saucepan, cook rhubarb with 1 ½ cup sugar and lemon zest, on stovetop on medium heat, until tender, (about 15 minutes).
- Combine ½ cup sugar and with cornstarch, stir into cooked rhubarb.
- Continue cooking for about 5-10 additional minutes, until rhubarb has broken down. Cool
- To achieve a pink color, add food colouring, if desired
- Preheat oven to 375 degrees F/190 degrees C. Spray a 9X13 pan with non-stick cooking spray.
Base
- In a large mixing bowl, stir flour, baking soda, brown sugar and oats together. Cut in cold butter.
- Pat ½ the mixture into the bottom of the pan.
- Then add rhubarb filling mixture on top. Spread evenly with a rubber spatula.
- Add remaining flour/oat crumb topping mixture over rhubarb layer.
- Bake in preheated oven for 35 - 45 minutes or unti lightly browned.
- Cool and cut into squares. Serve with a dollop of whipped cream and a sprinkle of cinnamon, if desired. Hint: It's important to wait until rhubarb squares are completely cooled before cutting, otherwise they will fall apart. You can put them in the freezer to speed up the process!
Linda
This compote was way too sweet and I had used extra rhubarb and only 1+1/3 cups sugar! I added several apples to the mix and made a crumble from it.
Ken
These were easy to make and the recipe was very easy to follow. They turned out well, but my family and I thought they were too sweet. You lose the unique tartness of the rhubarb. I might try again with perhaps another cup of rhubarb and/or less sugar. Thank you for sharing the recipe though!!
Terri Gilson
Hi Ken,
Glad the recipe was easy to follow. Yes, you have to add quite a bit of sugar to rhubarb to balance the tart- I've never had anyone else say they were too sweet, though. I woudl definitely cut the sugar for your family!
Terri
Cindy
Do these freeze well?
Terri Gilson
Hi Cindy: Yes they do!
Fouzia Husainy
The rhubarb crumble looks tempting. Just waiting for the rhubarb season to come to make this recipe. Thank you for sharing
Asha
These are scrumptious! And sure didn't last long. Such a great way to use up my remaining frozen rhubarb before restocking this summer.
Bernice
These squares look delightful! Would you believe I still have rhubarb in the freezer and my rhubarb plant is already up. Bring on rhubarb season!
Cindy Mom the Lunch Lady
These squares remind me of the ones my Mom use to make for us growing up. They were always so yummy. I am so excited to see my rhubarb sprouting in the garden!
Judy
I love rhubarb anything! I can’t wait to try it. Looks awesomely delicious 😊
Terri Gilson
Hope you enjoy them, Judy! Please come back after you try them and leave a rating if you love them!
Terri
Vanessa
I'm adding this to the list of things that I need to make with my rhubarb this year! I can't wait! Thanks for the easy to follow directions and the tip on grating the butter.
Gail Benjamin
Hi Terry. I just made this recipe. (July 7,2024) It’s a keeper. Just the way I’d want an oatmeal rhubarb square to taste.
Terri Gilson
Glad to hear you loved it, Gail!
Terri