Plum Oatmeal Bars With Crumble Topping layer a tart plum filling with a crunchy sweet buttery, oat-filled crust seasoned with cinnamon. These bars are sure to be a new summer favorite.
Serve these plum streusel bars warm, cold, or at room temperature. Top them with ice cream for an easy summer dessert.
Because they have so little added sugar they also work as plum breakfast bars.
If you like these plum crumble bars you will also want to check out these Fresh Peach Oatmeal bars.
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Why You Will Love This Recipe
- Juicy sweet plums are surrounded by buttery crunchy streusel.
- This easy recipe uses the same mix for both the crust and topping.
- These plum bars make a great breakfast or top them with ice cream for a delicious dessert.
- All you need are few simple ingredients to make these plum cobbler bars.
Looking for more delicious summery desserts? Try one of these: Rhubarb Chocolate Cake, Fresh Raspberry Cupcakes, Chocolate Cupcakes with Strawberry Filling, Chocolate Peanut Butter Swirl Ice Cream, and Sweet Corn Creme Brulee.
Recipe Ingredients
Old Fashioned Oats: Do not use instant or steel-cut oats. Old-fashioned oats are the perfect size and texture for these bars.
Salt: I add at least a pinch of salt to all of my recipes. Salt complements and intensifies the other flavors. For all of my recipes, I use Morton Kosher Salt which packs more densely than Diamond Crystal Kosher Salt. If you are using Diamond Crystal Kosher Salt you will want to double the amount of salt you add.
Unsalted Butter: I prefer to use unsalted butter when baking. The amount of salt in butter can vary from brand to brand. By using unsalted butter and adding salt separately I can control how much salt is added to the recipe,
Plums: Look for plums that are heavy for their size, smooth, and without blemishes. Avoid plums that are shriveled or have spots and discoloration. Ripe plums will be slightly soft.
You can ripen firm plums in a paper bag at room temperature but you should avoid plums that are excessively hard as they were harvested prematurely and will never ripen properly.
Ripe plums can be refrigerated for up to four days. Before eating allow plums to return to room temperature for maximum juiciness and sweetness.
Corn Starch: Cornstarch is used to thicken the plumb juice while the bars bake. It does not need to be dissolved in additional liquid and can be sprinkled over the fruit before adding the final layer.
See the recipe card for full information on ingredients and quantities.
Substitutions and Variations
Flour: To make these bars gluten-free use gluten-free oats and substitute almond flour for the all-purpose flour.
Nuts: Add a ½ cup of chopped nuts to the crust.
Plums: Substitute a good plum jam in place of the fresh plums.
Fruit: Substitute your favorite stone fruit like peaches, nectarines, or apricots for the plums.
Step by Step Directions
Step 1: Line a 9 x 9-inch baking pan with parchment paper allowing the ends to extend over two of the sides, spray with nonstick spray, and set aside. Heat oven to 375°F (190°C) and position an oven rack at the top of the oven.
Step 2: In a large mixing bowl, stir together the oats, all-purpose flour, sugar, brown sugar, baking powder, cinnamon, and salt.
Step 3: Add the melted butter and vanilla to the dry ingredients. Stir until crumbly.
Step 4: Press half of the dough into the bottom of the pan in an even layer.
Step 5: Bake for 10-12 minutes or until lightly golden brown on the edges.
Step 6: While the crust is baking, chop the plums into 1-inch pieces. Layer the chopped plums over the baked crust and sprinkle with the cornstarch.
Step 7: Top with the remaining crumb mixture.
Step 8: Bake for 30-40 minutes until the crust is light golden brown.
Cool completely then refrigerate for one hour. Use the parchment paper to lift the bars from the pan for easy cutting and cut them into squares.
Recipe FAQs
I don't the tart flavor of the skin provides a nice contrast to the sweet crust.
For neater slices, allow the bars to cool for at least an hour before cutting. This will allow the plum filling to set. Use the parchment paper sling to lift the bars from the baking pan. Use a large serrated knife to easily cut even pieces.
Refrigerator: Store the plum bars in the refrigerator in an airtight container for up to one week.
Freezer: Cool the plumb bars completely and cut them into squares.
Place the squares on a wax paper or parchment paper-lined baking sheet and freeze until solid, about 2 hours.
Layer the bars in a storage container separating each layer with sheets of wax paper or parchment paper. Bars can be frozen for up to 3 months.
To Thaw: place in the refrigerator overnight.
Expert Tips
- Make the crumb base/topping ahead of time and store it in the refrigerator or freezer. You can also double the recipe and keep extra in your freezer for future use.
- Substitute a good plum jam in place of the fresh plums.
- Baking times for all recipes are only suggestions. The actual baking time will vary depending upon your oven. It is helpful to know your oven and worth purchasing an inexpensive oven thermometer. Oven temperatures can vary as much as 50 degrees plus or minus.
- Refrigerating the bars for at least an hour before cutting ensures easy clean cuts.
- Substitute your favorite stone fruit like peaches, nectarines, or apricots for the plums.
More Dessert Recipes
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📖 Recipe
Plum Oatmeal Bars With Crumble Topping
Equipment
- mixing bowl
- parchment paper
Ingredients
Base/Topping
- 2 cups old fashioned rolled oats
- 1 cup all-purpose flour
- ½ cup granulated white sugar
- ½ cup brown sugar
- 1 teaspoon baking powder
- 1 teaspoon cinnamon
- ½ teaspoon kosher salt
- 1 cup melted unsalted butter 2 sticks
- 1 teaspoon vanilla extract
Plum Filling
- 6 plums
- 1 tablespoon cornstarch
Instructions
- Step 1: Line a 9 x 9-inch baking pan with parchment paper allowing the ends to extend over two of the sides, spray with nonstick spray, and set aside. Heat oven to 375°F (190°C) and position an oven rack at the top of the oven.
- In a large bowl, stir together the 2 cups old fashioned rolled oats, 1 cup all-purpose flour, ½ cup granulated white sugar, ½ cup brown sugar, 1 teaspoon baking powder, 1 teaspoon cinnamon, and ½ teaspoon kosher salt. Add the 1 cup melted unsalted butter and 1 teaspoon vanilla extract. Stir until crumbly.
- Press half of the dough into the bottom of your baking pan and bake for 10-12 minutes or until lightly golden brown on the edges.
- While the crust is baking, chop the 6 plums into 1-inch pieces. Layer the plums over the baked crust and sprinkle with the 1 tablespoon cornstarch. Top with the remaining crust mixture.
- Bake for 30-40 minutes until the crust is light golden brown.
- Cool completely then refrigerate for one hour. Use the parchment paper to lift the bars from the pan and cut them into squares.
Bev says
I have not made these yet. I am wondering if you come freeze before you bake the squares …would the affect the way it turns out?
Erica Schramek says
I have never tried freezing them before baking. I don't think it should affect the out come. If you bake from frozen you will probably need to increase the bake time. Let me know how it turns out.
Carrie says
Really delicious! Trying to cut back on sugar so I didn’t do the full amount of white or brown sugar and it was still great.
The only thing that could help would be a measurement of the plums. Ours are really small so using 6 wouldn’t have been enough. I just kept cutting more until it covered the base
Erica Schramek says
I am really glad you liked them.
Heidi R says
So nice to have the crust and crumb topping with the same mix. This is so good with plums.
Erica Schramek says
You've go to keep things simple where you can. I am so happy you enjoyed them.