These Amish Rhubarb Crisp Squares are a classic old-fashioned dessert with a buttery, crumbly crust, a sweet-tart rhubarb filling, and a golden oat topping. Fresh rhubarb becomes wonderfully tender as it bakes, while the crisp topping adds just the right amount of sweetness and crunch.
Simple, comforting, and easy to cut into squares, this recipe is perfect for spring and summer gatherings, church suppers, potlucks, bake sales, or an everyday homemade dessert.
Why You’ll Love These Rhubarb Crisp Squares
- Sweet and tangy rhubarb filling
- Buttery oat crumble topping
- Easy to slice and serve
- Perfect for fresh rhubarb season
- Great for potlucks and family gatherings
- Can be made ahead
- Delicious warm or chilled
Ingredients
For the Crust and Crisp Topping
- 2 cups all-purpose flour
- 1 1/2 cups old-fashioned rolled oats
- 1 cup packed brown sugar
- 1 cup unsalted butter, melted
For the Rhubarb Filling
- 4 cups fresh rhubarb, chopped
- 1 cup granulated sugar
- 1/4 cup all-purpose flour
- 1 teaspoon vanilla extract
How to Make Amish Rhubarb Crisp Squares
Step 1: Prepare the Oven
Preheat your oven to 350°F.
Line a 9×13-inch baking pan with parchment paper, leaving some overhang for easy removal. Lightly grease the parchment.
Step 2: Prepare the Rhubarb
Wash the rhubarb stalks and trim away the leaves and ends.
Cut the stalks into approximately 1/2-inch pieces.
Place the chopped rhubarb in a large bowl and toss with the granulated sugar, flour, and vanilla.
Set aside for a few minutes while preparing the crust.
Step 3: Make the Crumble Mixture
In a large bowl, combine the flour, rolled oats, and brown sugar.
Pour in the melted butter and stir until the mixture becomes evenly moistened and crumbly.
Step 4: Form the Bottom Crust
Press approximately two-thirds of the crumble mixture firmly into the bottom of the prepared baking pan.
Make sure the layer is even and compact.
Reserve the remaining crumble mixture for the topping.
Step 5: Add the Rhubarb
Spread the prepared rhubarb mixture evenly over the crust.
Distribute it from edge to edge so every square will have plenty of filling.
Step 6: Add the Crisp Topping
Sprinkle the remaining crumble mixture evenly over the rhubarb.
Don’t press the topping down too firmly. Keeping it loose helps create a crumbly, crisp texture.
Step 7: Bake
Bake for approximately 40–50 minutes, or until the rhubarb filling is bubbling and the topping is golden brown.
If the topping begins browning too quickly, loosely cover the pan with foil for the remaining baking time.
Step 8: Cool
Remove the pan from the oven and allow the dessert to cool completely.
For the cleanest squares, refrigerate it for about 1 hour after cooling.
Step 9: Slice and Serve
Use the parchment paper to lift the dessert from the pan.
Cut into squares and serve.
Tips for Perfect Rhubarb Crisp Squares
Use fresh rhubarb when possible. Look for firm, brightly colored stalks.
Don’t use rhubarb leaves. Rhubarb leaves should be discarded.
Cut the rhubarb evenly. Pieces around 1/2 inch cook at a similar rate and create a pleasant texture.
Allow the squares to cool. The filling thickens considerably as it cools, making the bars easier to cut.
Use old-fashioned oats. They provide a hearty texture and better structure than quick oats.
Don’t pack down the topping. A loose layer produces a more traditional crisp texture.
Easy Variations
Strawberry Rhubarb Crisp Squares
Replace 1 cup of the rhubarb with chopped fresh strawberries for a classic strawberry-rhubarb combination.
Cinnamon Rhubarb Squares
Add 1/2 teaspoon ground cinnamon to the crumble mixture.
Vanilla Rhubarb Crisp
Add an additional splash of vanilla to the filling for a sweeter aroma.
Pecan Crisp Squares
Add 1/2 cup chopped pecans to the topping for extra crunch.
Brown Sugar Rhubarb Filling
Replace part of the granulated sugar with brown sugar for a deeper caramel-like flavor.
How to Serve Amish Rhubarb Crisp Squares
These squares are delicious at room temperature, but they are especially comforting while slightly warm.
Serve them with:
- Vanilla ice cream
- Whipped cream
- Plain yogurt
- Fresh strawberries
- A drizzle of cream
A warm square topped with vanilla ice cream makes an especially satisfying dessert.
How to Store
Place cooled rhubarb crisp squares in an airtight container.
Because the filling contains fresh fruit, refrigerate the bars and enjoy them within 3–4 days.
The topping will soften somewhat in the refrigerator but will still remain delicious.
Can You Make Them Ahead?
Yes. These squares are ideal for making ahead.
Bake them the day before serving and refrigerate once completely cooled. Bring them close to room temperature before serving, or warm individual pieces gently in the oven.
Can You Freeze Rhubarb Crisp Squares?
Yes. Allow the baked crisp to cool completely before freezing.
You can freeze the entire pan or individual squares. Wrap tightly and place in a freezer-safe container.
Freeze for up to 2–3 months for the best quality.
Thaw overnight in the refrigerator and warm gently before serving.
Frequently Asked Questions
Can I use frozen rhubarb?
Yes. Frozen rhubarb can be used, but thaw and drain it well first to prevent excess liquid from making the filling watery.
Why are my rhubarb squares runny?
Rhubarb naturally releases liquid as it cooks. Allowing the squares to cool completely gives the filling time to thicken. Using the recommended amount of flour also helps absorb excess moisture.
Can I use quick oats?
Yes, although old-fashioned rolled oats generally provide a more substantial, crisp topping.
Why is my topping not crispy?
Too much moisture can soften the topping. Make sure the rhubarb is not excessively wet and allow the dessert to cool uncovered after baking.
Can I make this without oats?
Yes. You can replace the oats with additional flour, although the topping will have a different texture.
Recipe at a Glance
Recipe: Amish Rhubarb Crisp Squares
Prep Time: 15 minutes
Bake Time: 40–50 minutes
Cooling Time: 1 hour
Total Time: About 2 hours
Servings: 16 squares
Oven Temperature: 350°F
Final Thoughts
Amish Rhubarb Crisp Squares are a wonderful way to turn fresh rhubarb into a comforting homemade dessert. The tart rhubarb filling balances beautifully with the buttery brown sugar and oat crumble, creating a dessert that is simple, rustic, and satisfying.
Whether you’re baking for a family gathering, a potluck, or simply looking for a delicious way to use seasonal rhubarb, these crisp squares are an old-fashioned favorite worth making again and again.