Gluten-Free Strawberry Rhubarb Bars Recipe for Spring Baking

These gluten free strawberry rhubarb bars are a favorite spring and summer bake. A buttery gluten-free shortbread crust is pressed into a 9×13 pan and pre-baked until just golden. A bright, sweet-tart strawberry and rhubarb filling—lifted with fresh lemon juice and thickened with arrowroot or cornstarch—is spread over the warm crust, then the reserved crumb mixture and sliced almonds are scattered on top before a final bake until the filling is bubbly and the top is golden.

One of the nicest things about this recipe is that the shortbread dough doubles as both the crust and the crumb topping, so you only need two bowls and a single crust recipe to make the whole dish.

These bars are ideal for making ahead, which makes them a great gluten free dessert to bring to spring gatherings, potlucks, or summer parties.

I usually make them the day before serving: let them cool completely, refrigerate overnight so they set up well, and slice into neat bars just before serving.

Serve chilled from the refrigerator, or warm slightly and add a scoop of vanilla ice cream or a dollop of whipped cream for an extra-treat finish.

Ingredients

Gluten free flour
Unsalted butter
Coconut oil (melted)
Vanilla extract
Granulated sugar
Brown sugar
Sea salt
Strawberries, hulled and diced
Rhubarb, diced
Fresh lemon juice
Arrowroot powder or cornstarch (thickener)
Sliced almonds

1. Preheat the oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter or coconut oil and set aside.

2. In a large bowl, combine the diced strawberries, diced rhubarb, lemon juice, the smaller portion of granulated sugar, and arrowroot powder (or cornstarch). Stir to coat and set aside, stirring occasionally while you prepare the crust.

3. In the bowl of a stand mixer (or a large bowl using a hand mixer), combine the gluten free flour, unsalted butter, melted coconut oil, vanilla extract, granulated sugar, brown sugar, and salt. Mix until the mixture becomes crumbly.

4. Reserve 1 cup of the crumbly mixture for the topping.

5. Press the remaining crumb mixture firmly into the bottom of the prepared 9×13 pan using your hand, the bottom of a measuring cup, or a glass. Bake the crust at 375°F for 15–18 minutes, until it is lightly browned. Remove and let the crust cool for 10 minutes.

6. Stir the fruit mixture again and pour it evenly over the cooled crust. Sprinkle the reserved crumb mixture over the fruit, then scatter the sliced almonds on top.

7. Return the pan to the oven and bake at 375°F for 30–35 minutes, until the top is golden and the fruit filling is bubbly around the edges.

8. Remove from the oven and allow the bars to cool completely. For best results, chill in the refrigerator for a few hours or overnight to let the filling set before slicing into bars.

9. Serve chilled or slightly warmed with vanilla ice cream or whipped cream, if desired.

Supplies

9×13-inch baking dish, large mixing bowls, stand mixer or hand mixer (optional), measuring cups and spoons, spatula, and a measuring cup or glass to press the crust.

Storage

Store the bars covered or in an airtight container in the refrigerator for 3–5 days. Because the filling contains fresh fruit, refrigeration is necessary; do not leave the bars at room temperature for more than a couple of hours. Individual bars keep well in small glass containers for easy grab-and-go snacks or lunchbox treats.

Top Tip

Let the pre-baked shortbread crust cool for the full 10 minutes before adding the fruit filling. Pouring the filling over a very hot crust can make the bottom soggy and cause the bars to lose shape. While the crust cools, stir the fruit mixture to ensure the juices are evenly distributed before spreading it over the crust.

Yes. These bars are best made the day before serving so the filling can set in the refrigerator. Bake, cool completely, cover, and refrigerate overnight. Slice and serve chilled or slightly warmed with ice cream or whipped cream.

Yes. Thaw frozen fruit completely and drain excess liquid, then pat dry before using. Too much moisture can make the filling runny. Fresh fruit gives the best texture, but frozen works well if prepared carefully.

Absolutely. Chopped pecans or walnuts are good substitutes, or omit nuts entirely for a nut-free version. Nuts add crunch and a toasty flavor but are optional.

Chill the bars thoroughly before slicing—ideally a few hours or overnight. Use a sharp knife and wipe the blade between cuts for the cleanest results.

Yes. You can halve the recipe and bake in an 8×8 or 9×9 pan. Baking times may be slightly shorter; watch the crust and filling closely during both bakes.

Yes. Cornstarch works as a one-to-one substitute for arrowroot powder to thicken the fruit filling and help it set.

If you try these Gluten Free Strawberry Rhubarb Bars, leave a comment and rating to share how they turned out and what you served with them.