Rhubarb Pie with Oat Streusel Topping Recipe

Why I Love Rhubarb Pie

Growing up on a farm, making pies from scratch was woven into everyday life. My mother would pull a warm pie from the oven and we never tired of it. Rhubarb was always a favorite. The first stalks I harvest each season still feel like a signal: it’s time to make this pie. It’s simple, nostalgic, and exactly what I want when rhubarb is at its best.

What makes this rhubarb pie special: Instead of a traditional double crust, it’s finished with an oat streusel topping, which makes the pie easier to assemble and adds a crisp, buttery contrast to the jammy filling.

There’s something satisfying about piling a tall mound of rhubarb into the crust and watching it transform in the oven into a spoonable, jam-like filling. The oat streusel melts and browns into crunchy clusters while the rhubarb sweetens and softens. The result is a bright, tangy pie with a rustic crumble finish—comforting and reliably delicious.

Why you’ll love this recipe:

• All-rhubarb filling that lets the natural tartness shine, without relying on strawberries or other fruits.
• Generous filling—6 cups of diced rhubarb bake down into a thick, jammy interior rather than a thin layer of fruit.
• Oat streusel topping that yields a crisp, crumble-like finish, combining the best parts of pie and fruit crisp in one dessert.
• Make-ahead friendly—the pie slices more cleanly once fully cooled, so you can bake it earlier in the day and serve perfect wedges after dinner.

Rhubarb Pie Ingredients

These ten ingredients create the bright, textured pie described here:

• All-purpose flour – gives the streusel structure so it bakes into crispy clumps.
• Old-fashioned rolled oats – add chew and a nutty character to the topping.
• Light brown sugar – sweetens the streusel and lends a caramel note.
• Unsalted butter – cold butter produces chunky, bakery-style crumbs in the streusel.
• Kosher salt – balances sweetness and enhances flavor.
• Pie crust – use a sturdy 9-inch all-butter crust or your favorite prepared crust to hold the tall filling.
• Rhubarb – diced small so it softens evenly and yields that jammy texture.
• Granulated sugar – sweetens the tart rhubarb while preserving a pleasant tang.
• Instant tapioca – thickens the juices so slices hold together; cornstarch can be used as an alternative.
• Fresh orange juice – brightens and lifts the rhubarb with a subtle citrus note.

Exact quantities appear in the recipe card below.

How to Make Rhubarb Pie

Follow these straightforward steps once your pie crust is ready:

Make the streusel – Combine flour, oats, brown sugar, and salt. Cut cold butter into 1/4-inch pieces and work it in until only pea-sized bits remain. Chill while you prepare the filling.

Mix the filling – Toss diced rhubarb with granulated sugar, instant tapioca (or cornstarch), fresh orange juice, and salt until evenly coated.

Fill the crust – Fit the chilled pie crust into a 9-inch pie dish. Pour in the rhubarb mixture; it will look very full but the fruit reduces significantly as it bakes. Scatter the chilled streusel evenly over the top, pressing lightly so it adheres but stays crumbly. Place the pie on a parchment-lined baking sheet to catch any drips.

Bake – Start in a preheated 400°F oven for 10 minutes, then lower to 375°F and continue baking until the streusel is deep golden and the filling bubbles toward the center, about 70–80 minutes total.

Cool completely – Let the pie cool on a rack for at least four hours so the filling thickens and slices cleanly. Use a sharp or serrated knife to cut neat wedges.

Recipe Tips

• Prep the rhubarb – Wash, dry, and trim stalks; dice into 1/4-inch pieces so they cook evenly.
• Use a baking sheet – The pie is tall and juicy; a parchment-lined sheet under it saves the oven from drips and makes cleanup easier.
• Wait for the center to bubble – The pie should bubble through the middle so the thickener activates; don’t remove it too early.
• Shield the crust if needed – If edges brown before the filling is done, loosely cover them with foil or a pie shield.
• Cool for clean slices – Allowing the pie to cool for four hours produces cleaner, prettier slices; cutting too soon yields a delicious but messy pie.

Follow These Tips

Serving

After cooling at least four hours, serve the pie at room temperature or slightly warm so the filling remains thick. Top slices with a scoop of vanilla ice cream, a dollop of whipped cream, or a spoonful of Greek yogurt.

Storage

Refrigerate – Once fully cooled, cover and refrigerate up to four days. The streusel will soften slightly but the flavors deepen.

Freeze – Freezing is possible but not ideal. Freeze individual slices on a parchment-lined tray, then wrap tightly and store in a freezer-safe container up to two months.

Reheat – Warm single slices in the microwave for 20–30 seconds, or enjoy the pie at room temperature or chilled.

More Pie Recipes

• Classic apple pie
• Oatmeal nut pie
• Easy blueberry galette
• Classic pumpkin pie
• Blueberry pie with streusel topping
• Peach blackberry pie
• Sour cream raisin pie

Have I Convinced You to Make This Recipe?

I hope you try this pie and enjoy it at your table. Leave a comment and a star rating to let others know how it turned out—your feedback helps home bakers decide whether to try it themselves.