Old-Fashioned rhubarb bars, with a shortbread base and a rhubarb custard topping. A classic and a great use for fresh or frozen rhubarb.

rhubarb bars cut on serving board

Why you’ll love these rhubarb bars

  • These old-fashioned rhubarb bars are the perfect meeting of sweet and sour.
  • The rhubarb sits in a lovely custard base, all on top of a shortbread base.
  • These rhubarb bars can be made with either fresh or frozen rhubarb.

Ingredients and Substitutions

Rhubarb – you can use either fresh or frozen rhubarb for these bars. If frozen, use from frozen and allow a bit of extra baking time.

Step-by-Step Photos

  1. Combine the ingredients for the shortbread base in a bowl.
  2. Cut the butter into the dry ingredients until crumbly.
  3. Press the shortbread base into a parchment-lined 8×8-inch baking pan and bake for 10 minutes.
  4. Meanwhile, combine the ingredients for the topping in a bowl and stir together with a fork.
  5. Add the diced rhubarb to the bowl and stir in.
  6. Remove the base from the oven and pour the topping over top. Return to the oven and bake a further 35-40 minutes, or until set and golden.
old-fashioned rhubarb bars on serving board

Making ahead, Storing and Freezing

These rhubarb bars keep well. I like to store them in the refrigerator.

These will also freeze well, for up to 2 months.

rhubarb bars cut on serving board

Get the Recipe: Old-Fashioned Rhubarb Bars

Classic, old-fashioned rhubarb bars, with a shortbread base and a rhubarb custard topping. Can be made with fresh or frozen rhubarb.
5 stars from 1 rating
Prep Time: 15 minutes
Cook Time: 45 minutes
Total Time: 1 hour
Yield: 16 servings


For the base:

  • 3/4 cup all purpose flour, spooned and levelled
  • 6 Tablespoons butter, cold and cut into 6 pieces
  • 3 1/2 Tablespoons icing/confectioners' sugar

For the topping:

  • 1 1/2 large eggs, very lightly beaten *see Note 1 below
  • 3 Tablespoons all purpose flour
  • 1 cup + 2 Tablespoons granulated white sugar
  • 1 1/4 cups rhubarb, finely chopped, fresh or frozen


  • Preheat oven to 350F (regular bake setting/not fan-assisted).
  • Spray an 8×8 baking pan with baking spray and line with parchment paper. Set aside.
  • Make base by combining the base ingredients in a medium bowl. Using your fingertips or a pastry cutter, cut the cold butter into the dry ingredients until you have a crumbly mixture with pea-sized pieces of butter. Press the mixture into the bottom of the prepared pan. Bake in preheated oven for 10 minutes.
  • Meanwhile, add the eggs to a medium bowl and stir gently with a fork. Add the flour and sugar and stir together with a fork. Add the rhubarb and stir to combine.
  • When base has pre-baked, remove from oven and pour filling over-top. Use a spoon to spread out evenly over the base.
  • Return the pan to the oven and bake a further 35-40 minutes, until lightly golden and the tip of a butter knife inserted in the centre comes out clean. (Frozen rhubarb will take a few minutes extra baking generally).
  • Remove from oven and allow to cool completely in the pan before slicing into squares. Garnish with icing/confectioners' sugar, if desired.
  • (I like to store these in the refrigerator. You can also freeze up to 2 months).


Note 1: To get 1/2 an egg, break an egg into a small bowl, stir together with a fork and use just 1/2 of it (you can eyeball it).
You can double the recipe (use the “2X” button) and bake in a 9×13-inch pan.
Be sure to read the notes above this Recipe Card, for more tips on making this recipe, as well as step-by-step photos that you might find useful. 
Cuisine: American, Canadian
Course: Dessert
Serving: 1serving, Calories: 144kcal, Carbohydrates: 24g, Protein: 1g, Fat: 5g, Saturated Fat: 3g, Polyunsaturated Fat: 0.3g, Monounsaturated Fat: 1g, Trans Fat: 0.2g, Cholesterol: 29mg, Sodium: 41mg, Potassium: 43mg, Fiber: 0.4g, Sugar: 18g, Vitamin A: 166IU, Vitamin C: 1mg, Calcium: 13mg, Iron: 0.5mg
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