Gluten-Free Rhubarb Crisp

5 from 6 votes

Gluten-free rhubarb crisp made with tart rhubarb and a buttery buckwheat oat topping. A simple spring dessert that bakes until bubbling.

Prep Time20

Cook Time45

Total Time1 5

Course: Dessert

Cuisine: American / Canadian

Servings: servings

Calories: 388kcal

Preheat the oven to 350ºF (180ºC) and lightly grease an 8-inch (20-cm) square or round baking dish with butter (see recipe notes). Set aside.
Place the chopped rhubarb in a large bowl, add the lemon juice, and stir to combine.
Stir the sugar and cornstarch together in a small bowl. Sprinkle the mixture over the rhubarb, stir well, and set aside.
In a second large bowl, combine the buckwheat flour, brown sugar, rolled oats, cinnamon, and salt. Mix with your hands, breaking up any large pieces of brown sugar with your fingers.
Add the butter to the oat mixture, then rub it in with your hands until no dry bits of buckwheat flour remain in the bottom of the bowl.
Stir the rhubarb once more, then spoon it into the prepared baking dish and spread it into an even layer. Sprinkle the buckwheat oat topping evenly over the rhubarb.
Bake for 40 to 45 minutes, or until the topping is golden and the rhubarb is bubbling around the edges. Cool the crisp on a wire rack for 15 minutes before serving warm with ice cream or whipped cream.

For detailed ingredient notes, substitution tips, variations, and step-by-step photos, scroll through the full recipe post.
Use a digital kitchen scale for precise measurements and an oven thermometer to confirm your oven is heating correctly.
To switch to gram measurements, click "Metric grams" in the ingredients section of the recipe card.
I used an 8-inch (20-cm) square baking dish for this recipe. If using a 9-inch (23-cm) square dish, increase the rhubarb to 5 cups (750 g) and expect the topping to bake in a slightly thinner layer.
Stir the rhubarb filling again before adding it to the baking dish, as the sugar and cornstarch can settle in the bottom of the bowl.

Store leftover crisp covered in the refrigerator for up to 3 days. Reheat individual portions in the microwave, or warm in a 300ºF (150ºC) oven until heated through. The topping will soften after refrigeration, but warming it in the oven can help bring back some texture.