Amish Oatmeal Rhubarb Bars With Crumb Topping for Spring Gatherings

Amish Oatmeal Rhubarb Bars Ingredients

Let’s gather everything we need for these beautiful bars. The recipe splits into two parts: the oat crumb base and topping, and the rhubarb filling. Each part uses simple pantry staples you likely already have on hand.

For the Crust and Topping

• 2 cups old fashioned rolled oats, Quaker works great. They give a chewy, hearty texture. Avoid instant oats, which can turn gummy.
• 1 cup all purpose flour, For structure that holds the bars together.
• 1 cup cold butter, Cut into small cubes. Cold butter is key for a crumbly topping.
• 1 cup brown sugar, Adds sweetness and moisture. Pack it firmly.
• 1 teaspoon salt
• 1 teaspoon baking soda

For the Rhubarb Filling

• 4 cups fresh or thawed frozen rhubarb, Chop into ½ inch pieces. If using frozen, drain excess moisture first. Never use the leaves, they are toxic to pets.
• 1 cup granulated sugar, Adjust based on your rhubarb’s tartness.
• 2 tablespoons cornstarch, Thickens the filling.
• ½ cup water
• 1 teaspoon vanilla extract
• 1 teaspoon ground cinnamon

These ingredients come together to create a sweet tart dessert that’s perfect for spring gatherings.

Step‑by‑Step Instructions for Amish Oatmeal Rhubarb Bars with Crumb Topping

Now let’s dive into the process. It’s straightforward and rewarding.

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1. Prepare the crumb base. In a large bowl, combine oats, flour, salt, baking soda, and brown sugar. Add the cold butter cubes. Use a pastry cutter or your fingers to work the butter into the dry ingredients until the mixture resembles coarse crumbs. Set aside one third of the mixture for the topping.
2. Press the base. Grease a 9×13 inch baking pan. Press the remaining two thirds of the crumb mixture firmly into the bottom of the pan. This creates a sturdy crust.
3. Make the rhubarb filling. In a medium saucepan, combine chopped rhubarb, sugar, cornstarch, and water. Cook over medium high heat, stirring frequently, until the mixture thickens and becomes glossy, about 5 to 10 minutes. Remove from heat and stir in vanilla and cinnamon. Let the filling cool slightly before spreading.
4. Assemble the bars. Spread the rhubarb filling evenly over the crust. Sprinkle the reserved crumb mixture on top.
5. Bake. Preheat your oven to 350°F (175°C). Bake for 30 to 40 minutes, rotating the pan halfway through for even browning. The topping should be golden brown and the filling bubbly.
6. Cool and slice. Let the bars cool completely in the pan, this takes about 1 to 2 hours. Cooling fully ensures clean, neat slices.

What to Serve with Best Amish Oatmeal Rhubarb Bars with Crumb Topping

These bars are wonderful on their own, but pairing them with something extra makes them even more special. Here are a few ideas:

• Vanilla ice cream, A scoop of creamy vanilla balances the tart rhubarb perfectly.
• Whipped cream, Light and airy, it adds a touch of elegance.
• Fresh berries, Strawberries or blueberries provide a fresh contrast.
• Hot coffee or tea, A warm drink brings out the sweet, spicy notes.
• Lemonade, For a refreshing, zesty pairing on a warm spring day.
• Dark chocolate, Shave some over the top for a decadent twist.

We love serving these bars warm with a scoop of vanilla ice cream, it’s a simple way to impress guests.

Make Ahead Options

Planning ahead is easy with this recipe. You can prepare both the crumb mixture and the rhubarb filling up to 24 hours in advance. Store the crumb mixture in an airtight container in the refrigerator, and keep the filling in a separate covered bowl in the fridge. When you’re ready to bake, simply press the base, spread the filling, sprinkle the topping, and pop the pan in the oven. This method gives you fresh, homemade bars with very little day of effort, perfect for busy mornings or last minute potluck invites.

Amish Oatmeal Rhubarb Bars with Crumb Topping Twists

Once you master the classic, feel free to experiment. Here are some fun variations to try:

• Berry Bliss, Replace half the rhubarb with fresh blueberries or raspberries.
• Apple Cinnamon, Substitute chopped tart apples for the rhubarb and increase the cinnamon.
• Nutty Crunch, Add ½ cup chopped walnuts or pecans to the crumb topping.
• Gluten Free, Use a 1 to 1 gluten free flour blend and certified gluten free oats.
• Honey Sweetened, Replace the sugar in the filling with ¾ cup honey or maple syrup.
• Citrus Zest, Add a teaspoon of lemon or orange zest to the filling for brightness.

These twists keep the recipe exciting and might become your new family favorite.

How to Store and Freeze Amish Oatmeal Rhubarb Bars

Proper storage keeps these bars fresh and delicious.

• Room temperature: Store covered for up to 2 days.
• Refrigerator: Place in an airtight container for up to 5 days.
• Freezer: Wrap individual bars tightly in plastic wrap, then place in a freezer bag. They keep for up to 3 months. To serve, thaw at room temperature or warm in the oven for a few minutes to restore the crunchy topping.

We like to keep a stash in the freezer for when a rhubarb craving strikes out of season.

Expert Tips for Amish Oatmeal Rhubarb Bars

• Use old fashioned oats. They give the best chewy texture. Instant oats can make the topping gummy.
• Keep butter cold. Cold butter cut into small cubes creates a flaky, crumbly texture. If the butter warms up, your topping won’t be as light.
• Cool the filling slightly. Spreading hot filling over the crust can cause it to soak in and make the base soggy.
• Press the base firmly. A well packed crust holds together better when you slice.
• Bake until golden and bubbly. The filling should be visibly bubbling around the edges. Rotate the pan halfway for even browning.
• Cool completely before slicing. Patience here pays off, you’ll get clean squares instead of a crumbly mess.

One more tip: reserve exactly one third of the crumb mixture for the topping. That ratio gives you the perfect balance of crust and crumble.

Amish Oatmeal Rhubarb Bars with Crumb Topping Recipe FAQs

Irresistible Amish Oatmeal Rhubarb Bars with Crumb Topping

Here’s the complete recipe at a glance, perfect for bookmarking or printing.

Ingredients

Crust and Topping

• 2 cups old fashioned rolled oats
• 1 cup all purpose flour
• 1 cup cold butter, cubed
• 1 cup brown sugar, packed
• 1 teaspoon salt
• 1 teaspoon baking soda

Rhubarb Filling

• 4 cups fresh or thawed frozen rhubarb, chopped (leaves removed)
• 1 cup granulated sugar
• 2 tablespoons cornstarch
• ½ cup water
• 1 teaspoon vanilla extract
• 1 teaspoon ground cinnamon

Instructions

1. Preheat oven to 350°F (175°C). Grease a 9×13 inch baking pan.
2. In a large bowl, combine oats, flour, salt, baking soda, and brown sugar. Cut in cold butter until mixture resembles coarse crumbs.
3. Reserve ⅓ of the crumb mixture for topping. Press remaining ⅔ firmly into the prepared pan.
4. In a saucepan, combine rhubarb, sugar, cornstarch, and water. Cook over medium high heat, stirring, until thick and glossy (5 10 minutes). Remove from heat; stir in vanilla and cinnamon. Let cool slightly.
5. Spread filling over crust. Sprinkle reserved crumbs over the top.
6. Bake 30 40 minutes, rotating pan halfway, until golden and bubbly.
7. Cool completely in the pan (1 2 hours) before slicing into 12 bars.

Store covered at room temperature up to 2 days, refrigerate up to 5 days, or freeze up to 3 months.

Amish Oatmeal Rhubarb Bars With Crumb Topping

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🍓 A rustic Amish-inspired dessert featuring a buttery oat crumble and a sweet-tart rhubarb filling that tastes like spring in every bite.
🌿 Perfect for potlucks, spring gatherings, or an afternoon coffee break — simple pantry staples make these bars wonderfully easy to pull together.

• Total Time: 2 hours 55 minutes
• Yield: 12 bars 1x

Ingredients

Scale 1x2x3x

2 cups old fashioned rolled oats

1 cup all purpose flour

1 cup cold butter

1 cup brown sugar

1 teaspoon salt

1 teaspoon baking soda

4 cups fresh or thawed frozen rhubarb

1 cup granulated sugar

2 tablespoons cornstarch

½ cup water

1 teaspoon vanilla extract

1 teaspoon ground cinnamon

Cook Mode Prevent your screen from going dark

Instructions

1-Prepare the crumb base: Combine oats, flour, salt, baking soda, and brown sugar; cut in cold butter until coarse crumbs form, then set aside 1/3 for topping.

2-Press the base: Grease a 9×13 inch pan and firmly press the remaining 2/3 of the crumb mixture into the bottom.

3-Make the rhubarb filling: Cook chopped rhubarb, sugar, cornstarch, and water over medium-high heat, stirring frequently, until thickened and glossy (5–10 minutes); remove from heat and stir in vanilla and cinnamon, then let cool slightly.

4-Assemble the bars: Spread the rhubarb filling evenly over the crust, then sprinkle the reserved crumb mixture on top.

5-Bake: Preheat oven to 350°F (175°C) and bake for 30–40 minutes, rotating the pan halfway through, until the topping is golden brown and the filling bubbly.

6-Cool and slice: Let the bars cool completely in the pan for 1–2 hours before slicing into neat squares.

Last Step:

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Notes

🧈 Keep butter cold while cutting it into the flour — this creates a flaky, crumbly topping rather than a dense one.
🥄 Use old-fashioned rolled oats for the best chewy texture; instant oats absorb too much moisture and can turn gummy.
⏲️ Cool the filling slightly before spreading and let baked bars cool completely before slicing to avoid a soggy base and crumbly mess.

• Author: Ruby Bennett
• Prep Time: 20 minutes
• Cooling Time: 2 hours
• Cook Time: 35 minutes
• Category: Dessert
• Method: Baking
• Cuisine: Amish
• Diet: Vegetarian

Nutrition

• Serving Size: 1 bar
• Calories: 370
• Sugar: 34g
• Sodium: 192mg
• Fat: 16g
• Saturated Fat: 10g
• Unsaturated Fat: 6g
• Trans Fat: 0g
• Carbohydrates: 54g
• Fiber: 2g
• Protein: 3g
• Cholesterol: 41mg