Amish Oatmeal Rhubarb Bars

These Amish Oatmeal Rhubarb Bars are a delightful combination of tangy rhubarb and a sweet, buttery oat crust. They are a classic farmhouse dessert that highlights the best of spring produce in a simple, handheld treat that the whole family will enjoy.

Why You Will Love This Recipe

There are so many reasons to fall in love with these Amish Oatmeal Rhubarb Bars. First, they offer the perfect balance of flavors; the tartness of the rhubarb filling is beautifully offset by the sugary, buttery crumble. Second, this recipe uses simple pantry staples like oats, flour, and brown sugar, making it an accessible bake for any day of the week. Finally, these bars are incredibly sturdy, making them ideal for potlucks, picnics, or school lunchboxes where you need a dessert that travels well.

Ingredients

• 4 cups fresh rhubarb, chopped into small pieces
• 1 cup granulated sugar
• 2 tablespoons cornstarch
• 1/2 cup water
• 1 teaspoon vanilla extract
• 1 1/2 cups all-purpose flour
• 1 1/2 cups rolled oats (old fashioned)
• 1 cup packed brown sugar
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• 3/4 cup unsalted butter, melted

Step-by-Step Instructions

1. Preheat your oven to 350°F (175°C) and grease a 9×9 inch square baking pan.
2. In a medium saucepan, combine the chopped rhubarb, granulated sugar, cornstarch, and water. Cook over medium heat, stirring constantly, until the mixture thickens and becomes clear.
3. Remove the rhubarb mixture from the heat, stir in the vanilla extract, and set aside to cool slightly.
4. In a large mixing bowl, whisk together the flour, rolled oats, brown sugar, baking soda, and salt.
5. Pour the melted butter over the dry ingredients and stir until the mixture is crumbly and well-combined.
6. Press half of the oat mixture firmly into the bottom of the prepared baking pan to create the crust.
7. Spread the cooked rhubarb filling evenly over the bottom crust.
8. Sprinkle the remaining oat mixture over the top of the rhubarb layer, pressing down very lightly.
9. Bake for 30 to 35 minutes, or until the top is golden brown.
10. Allow the bars to cool completely in the pan on a wire rack before cutting into squares.

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Expert Tips / Pro Tips

To ensure your Amish Oatmeal Rhubarb Bars turn out perfectly every time, make sure to chop the rhubarb into uniform half-inch pieces so they cook evenly in the filling. If your rhubarb is particularly tart, you can increase the sugar in the filling by a quarter cup. For the best texture, use old-fashioned rolled oats rather than quick oats; the larger flakes provide a much better “bite” and a more rustic appearance. Most importantly, do not rush the cooling process. If you cut these bars while they are still warm, the filling may be too soft and the bars will fall apart.

Variations & Substitutions

If you don’t have enough rhubarb, you can easily substitute half of it with sliced strawberries to make Strawberry Rhubarb Bars. For a gluten-free version, use a certified gluten-free flour blend and gluten-free oats. You can also add a teaspoon of cinnamon to the oat mixture for a warmer flavor profile, or toss in a half-cup of chopped walnuts or pecans for extra crunch in the topping.

Serving Suggestions

These bars are delicious on their own, but they can be elevated into a decadent dessert. Serve them slightly warm with a scoop of vanilla bean ice cream or a dollop of fresh whipped cream. They also pair wonderfully with a hot cup of coffee or tea for an afternoon snack. If you are serving them at a party, you can dust the tops with a little powdered sugar for a pretty, finished look.

Storage, Freezing & Reheating

Store any leftover Amish Oatmeal Rhubarb Bars in an airtight container at room temperature for up to two days, or in the refrigerator for up to five days. To freeze, wrap individual bars in plastic wrap and place them in a freezer-safe bag for up to three months. When you are ready to eat them, thaw the bars in the refrigerator overnight. To regain that fresh-baked texture, you can reheat individual bars in the microwave for 15-20 seconds or in a 300°F oven for 5-10 minutes.

Nutrition Information

FAQ

Can I use frozen rhubarb for this recipe?

Yes, you can use frozen rhubarb. Thaw it completely and drain off any excess liquid before measuring and cooking it with the sugar and cornstarch to prevent the filling from becoming too runny.

Do I need to peel the rhubarb?

No, there is no need to peel rhubarb. The skin softens significantly during the cooking and baking process and provides the beautiful pink color characteristic of rhubarb desserts.

Can I use quick oats instead of rolled oats?

While quick oats will work in a pinch, the texture will be softer and less chewy. Old-fashioned rolled oats are highly recommended for the best structural integrity and mouthfeel.

How do I know when the bars are done baking?

The bars are done when the edges are bubbling and the oat crumble on top has turned a beautiful golden brown color. This usually takes between 30 and 35 minutes.

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Amish Oatmeal Rhubarb Bars

A traditional Amish dessert featuring a sweet and tangy rhubarb filling sandwiched between two layers of buttery, chewy oatmeal crumble.

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Prep Time 20 minutes mins

Cook Time 40 minutes mins

Total Time 1 hour hr

Servings: 16 bars

Course: Dessert, Snack

Cuisine: American, Amish

Calories: 285

Ingredients Method Notes

Ingredients

  

Rhubarb Filling

• 4 cups Fresh Rhubarb
• 1 cup Granulated Sugar
• 2 tablespoons Cornstarch
• 1/4 cup Water
• 1 teaspoon Vanilla Extract

Oatmeal Crust and Topping

• 1.5 cups All-purpose Flour
• 1.5 cups Rolled Oats
• 1 cup Brown Sugar
• 1/2 teaspoon Baking Soda
• 1/4 teaspoon Salt
• 1 cup Unsalted Butter

Method

 

Instructions

1. Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking pan with butter or non-stick spray.
2. In a medium saucepan, combine the chopped rhubarb, granulated sugar, cornstarch, and water. Cook over medium heat, stirring constantly, until the mixture thickens and becomes clear. Remove from heat and stir in the vanilla extract.
3. In a large mixing bowl, whisk together the flour, rolled oats, brown sugar, baking soda, and salt until well combined.
4. Pour the melted butter over the dry ingredients and stir until the mixture is crumbly and the butter is evenly distributed.
5. Press half of the oatmeal mixture firmly into the bottom of the prepared baking pan to form the base crust.
6. Spread the cooked rhubarb filling evenly over the bottom crust layer.
7. Sprinkle the remaining oatmeal mixture over the top of the rhubarb filling, pressing down very lightly.
8. Bake for 35 to 40 minutes or until the top is golden brown. Allow the bars to cool completely in the pan before slicing into squares.

Notes

For the best results, use fresh rhubarb. If using frozen, thaw and drain thoroughly before measuring. These bars pair perfectly with a scoop of vanilla bean ice cream.