There’s a magical moment at the tail end of summer when the days are still warm, but the air carries the first crisp whisper of autumn. It’s during this time that stone fruits, particularly plums, reach their peak of juicy, jewel-toned perfection. What better way to celebrate this fleeting season than by baking them into something truly spectacular? These Oatmeal Plum Bars are the answer. They perfectly capture that sweet spot between a wholesome breakfast bake and an indulgent dessert, with a jammy, sweet-tart plum filling sandwiched between two layers of buttery, cinnamon-spiced oat crumble. They’re cozy, comforting, and an absolute dream with a cup of coffee or tea.
Why You’ll Love These Oatmeal Plum Bars
Aside from being ridiculously delicious, these bars have a lot going for them. They’re a staple in my kitchen for good reason, and I know you’ll fall in love too!
- The Perfect Texture Combo: You get the gooey, jammy fruit filling, the soft and chewy bottom oat layer, and the crisp, buttery crumble on top. It’s a trifecta of textural bliss in every single bite.
- Easy & Forgiving: This is not a fussy recipe! The crumble comes together in one bowl, and the filling is a simple simmer on the stovetop. It’s a fantastic recipe for bakers of all skill levels.
- Incredibly Versatile: Enjoy them warm from the pan for dessert (hello, vanilla ice cream!), let them cool completely for a sturdy snack bar, or even sneak one for a decadent breakfast. They do it all.
- Showcases Seasonal Fruit: This is the ultimate way to use up a bounty of fresh plums. The recipe lets their naturally sweet and tangy flavor be the star of the show.
Essential Ingredients & Equipment
The beauty of this recipe lies in its simple, pantry-friendly ingredients. Here’s what you’ll need to gather.
For the Jammy Plum Filling:
- Plums: About 1.5 pounds of fresh, ripe plums (any variety works!), pitted and chopped. You’re looking for about 4 cups of chopped fruit.
- Granulated Sugar: To sweeten the filling and help it break down into a jam. Adjust the amount based on the sweetness of your plums.
- Cornstarch: This is our secret weapon for a thick, luscious filling that won’t make the bars soggy.
- Lemon Juice: A squeeze of fresh lemon juice brightens up the plum flavor and balances the sweetness.
- Water: Just a splash to get the plums cooking.
For the Buttery Oatmeal Crumble:
- Old-Fashioned Rolled Oats: For that signature chewy texture and wholesome flavor. Do not use instant or steel-cut oats.
- All-Purpose Flour: Provides the structure for our crumble base and topping.
- Brown Sugar: Light or dark brown sugar adds moisture and a wonderful caramel note.
- Ground Cinnamon: The perfect warm spice to complement the plums. A pinch of nutmeg or cardamom is also lovely!
- Baking Soda: Gives the crumble a little bit of lift and tenderness.
- Salt: A pinch of fine sea salt enhances all the other flavors.
- Unsalted Butter: Make sure it’s cold and cut into small cubes. This is crucial for creating a tender, crumbly texture.
Equipment Needed:
- 8×8 inch or 9×9 inch square baking pan
- Parchment paper
- Medium saucepan
- Large mixing bowl
- Pastry blender or your fingertips
Step-by-Step Instructions
Ready to bake? Let’s walk through it step by step. It’s easier than you think!
- Preheat and Prep: Preheat your oven to 375°F (190°C). Grease your baking pan and line it with parchment paper, leaving an overhang on two sides to act as “handles” for easy removal later.
- Make the Plum Filling: In a medium saucepan, combine the chopped plums, granulated sugar, cornstarch, lemon juice, and water. Stir to combine and bring to a simmer over medium heat. Cook, stirring occasionally, for 8-10 minutes, or until the plums have broken down and the mixture has thickened into a jam-like consistency. Remove from heat and set aside to cool slightly.
- Prepare the Oatmeal Crumble: In a large bowl, whisk together the rolled oats, all-purpose flour, brown sugar, cinnamon, baking soda, and salt.
- Cut in the Butter: Add the cold, cubed butter to the dry ingredients. Using a pastry blender, two knives, or your fingertips, cut the butter into the mixture until it resembles coarse crumbs with some pea-sized butter pieces remaining. Don’t overmix!
- Assemble the Base: Take about two-thirds of the oatmeal crumble mixture and press it firmly and evenly into the bottom of your prepared baking pan. This will form your base layer.
- Add the Filling: Pour the slightly cooled plum filling over the oatmeal base and spread it into an even layer, leaving a small border around the edges.
- Add the Topping: Sprinkle the remaining one-third of the crumble mixture evenly over the top of the plum filling.
- Bake to Perfection: Place the pan in the preheated oven and bake for 35-45 minutes. The bars are done when the fruit filling is bubbly and the crumble topping is golden brown and firm to the touch.
- Cool Completely: This is the hardest part! You must let the bars cool completely in the pan on a wire rack for at least 2 hours. This allows the filling to set properly. If you cut them while warm, they will fall apart. Once cooled, use the parchment handles to lift the entire block out of the pan and cut into squares.
Pro Tips for Perfect Plum Bars
Want to take your bars from great to absolutely unforgettable? Keep these simple tips in mind.
- Don’t Skip the Cooling Time: I can’t stress this enough. For clean, neat slices that hold their shape, the bars must be completely cool. Patience is a virtue, and in this case, it’s a delicious one!
- Frozen Fruit Works Too: No fresh plums? No problem! You can use frozen, chopped plums. Just add them to the saucepan frozen and increase the cooking time by a few minutes to allow them to thaw and break down.
- Get Creative with Spices: While cinnamon is classic, feel free to add a pinch of ground ginger, nutmeg, or cardamom to the crumble mixture for a different flavor profile. A little almond extract in the filling is also divine!
- The “Press” is Important: When forming the base layer, make sure to press the crumble down firmly. This creates a sturdy foundation that won’t crumble when you cut into the bars.
Storing Leftovers
These bars are so good, you might not have any leftovers! But if you do, here’s how to keep them fresh.
At Room Temperature: The bars can be stored in an airtight container at room temperature for up to 3 days. This is the best way to maintain the crispness of the crumble.
In the Refrigerator: For longer storage, you can keep them in an airtight container in the refrigerator for up to a week. Note that the crumble will soften slightly in the fridge.
Freezing: These bars freeze beautifully! Once completely cooled, cut them into individual squares. Wrap each square tightly in plastic wrap, then place them in a freezer-safe bag or container. They will keep for up to 3 months. To enjoy, simply thaw at room temperature for a few hours.
Print
Oatmeal Plum Bars
- Total Time: 55 minutes
- Yield: 16 bars
- Diet: Vegetarian
Description
Chewy and buttery oatmeal bars layered with a sweet plum filling — a wholesome dessert or snack with fruity goodness in every bite.
Ingredients
1 1/2 cups old-fashioned rolled oats
1 1/4 cups all-purpose flour
3/4 cup brown sugar, packed
1/2 tsp baking soda
1/4 tsp salt
1/2 tsp ground cinnamon
3/4 cup unsalted butter, melted
1 1/2 cups chopped fresh plums (or use drained canned/plum jam)
2 tbsp granulated sugar
1 tbsp lemon juice
1 tsp cornstarch
1/2 tsp vanilla extract
Instructions
1. Preheat the oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper, leaving an overhang on two sides.
2. In a saucepan over medium heat, combine chopped plums, granulated sugar, lemon juice, and cornstarch. Cook for 8-10 minutes until the mixture thickens. Remove from heat and stir in vanilla extract. Let cool.
3. In a large bowl, mix oats, flour, brown sugar, baking soda, salt, and cinnamon.
4. Pour in the melted butter and stir until the mixture is crumbly and holds together when pressed.
5. Press two-thirds of the oat mixture into the bottom of the prepared pan to form a crust.
6. Spread the cooled plum filling evenly over the crust.
7. Sprinkle the remaining oat mixture on top and gently press it down.
8. Bake for 30-35 minutes or until golden brown.
9. Cool completely in the pan before lifting out and slicing into bars.
Notes
These bars can be stored in an airtight container at room temperature for up to 2 days or refrigerated for up to 5.
For easier cutting, chill the bars before slicing.
You can substitute the fresh plums with your favorite jam or other stone fruits.
- Prep Time: 20 minutes
- Cook Time: 35 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American