Rhubarb crumble pie squares

All the flavour, none of the fuss!

While I adore making (and eating) pie, I recognize that not everyone shares my fondness for fiddling with pastry. At this time of year, rhubarb pie is top of mind, so I wanted to create a dessert that offered all the deliciousness of this seasonal delight, in an easier format. Making a classic crumble mixture then using it as both the base and top layer with a yummy cooked rhubarb filling makes these squares both simple to make and super flavourful. Best of all, they’re gluten-free, thanks to the use of oat flour; you can swap in all-purpose flour if you prefer.


Rhubarb filling:

  • 3 cups (370 g) diced rhubarb (about 3 – 4 stalks)
  • 2 tablespoons (30 mL) water
  • 1 teaspoon (1.8 g) freshly grated gingerroot
  • 1/4 cup (50g) sugar, divided
  • 2 teaspoons (5.5 g) cornstarch

Base and top layer:

  • 2 cups (180 g) rolled oats
  • 2/3 cup (60 g) oat flour * (or all-purpose flour)
  • 1 teaspoon (4 g) baking powder
  • 1/2 teaspoon (3 g) salt
  • 1 cup (210 g) brown sugar
  • 1/2 cup (110 g) butter, melted
  • 1/2 teaspoon (2.5 mL) vanilla

*make oat flour by pulsing rolled oats in a food processor or blender


  • Preheat oven to 350F. Line an 8×8 inch (20×20 cm) baking pan with parchment paper and set aside.
  • Prepare rhubarb filling by placing rhubarb, water, ginger and 2 tablespoons (25 g) of the sugar in a medium pot. Place over medium heat and bring to a boil. Reduce heat to medium low and simmer for 5 minutes, stirring occasionally. Combine remaining sugar and cornstarch in a small bowl then stir into cooked rhubarb mixture. Let simmer for 3 – 4 minutes, until the mixture thickens. Remove from heat and set aside to cool.
  • In a large bowl, combine the rolled oats, oat flour, baking powder, salt and brown sugar. Stir to blend well. Drizzle in the melted butter and vanilla and stir until completely incorporated.
  • Spread half the oats mixture in the bottom of the prepared pan and pat down.
  • Drizzle the prepared rhubarb compote over the base layer. Sprinkle remaining oats mixture over the rhubarb and press down lightly with your fingertips.
  • Bake in preheated oven until top is uniformly golden brown and rhubarb bubbling, about 25 minutes.
  • Let stand at least 10 minutes, then slice into squares – you may find them easier to slice if you refrigerate for at least an hour.
  • Leftovers may be stored in an airtight container at room temperature for up to 3 days, or frozen for up to 2 months.

Makes sixteen one inch (2.5 cm) squares.

Author: Paula Roy

Welcome to my kitchen! I love simple dishes prepared with passion and am always seeking to find new methods to make food as fun and flavourful as possible. If you enjoy this space be sure to check out my Rogers TV Ottawa cooking show, Paula Roy's Favourite Foods, available on local cable, streaming and a dedicated playlist on Rogers TV's YouTube channel.

11 thoughts

  1. I don’t really bake, mostly because I don’t love sweets. Looking at me, you’d think I do! But I’m a savory gal through and through. But rhubarb is amazing and I’m keeping this recipe.

    1. I am more of a savoury gal too but my family loves sweets so I do bake fairly often for them. I am a huge fan of rhubarb and you’ll find several other of my favourite recipes (including roasted rhubarb and beet salad) on this site!

    1. Hi Cathy, I haven’t tried it yet but am quite confident you could do 50/50 strawberries and rhubarb as they have similar moisture content. Let me know how they work out!

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