These Gluten-Free Vegan Plum Crumble Bars are a summery dream come true. A cozy oatmeal crust and crumble sandwich a spiced homemade plum jam filling, letting the vibrant flavors of this underrated stone fruit truly shine. No fancy ingredients or complicated steps—just simple, delicious summer baking.

These Plum Crumble Bars have a delicious oatmeal crust and crumble topping that's filled with a simple plum jam. These simple bars highlight one of the summer's best stone fruits in a delicious gluten-free and vegan dessert.

Let’s just say it—I’ve been slacking on the plum recipes. Aside from my Summer Stone Fruit Crisp, plums have been flying solo in the archives. But after spotting juicy, jewel-toned plums and pluots at the San Diego farmer’s market last weekend, I knew I had to do them justice.

This recipe is a delicious love letter to summer stone fruits, especially plums, which are often overlooked in desserts. But not this time!

Why You’ll Love These Plum Bars

  • Naturally sweetened with maple syrup
  • Gluten-free + vegan, made with nourishing ingredients
  • Filled with homemade spiced plum jam
  • Easy to make and freezer-friendly
  • Perfect for picnics, snacks, or cozy afternoon tea
  • One dough = crust + crumble topping (easy win!)

Pst…if you love stone fruit recipes, you also need to try the best peach crisp ever!

These Plum Crumble Bars have a delicious oatmeal crust and crumble topping that's filled with a simple plum jam. These simple bars highlight one of the summer's best stone fruits in a delicious gluten-free and vegan dessert.

Plums are one of the juiciest, most underrated summer fruits. They’re tart, sweet, and so flavorful when cooked down, especially when paired with a touch of maple syrup, vanilla, and cinnamon. You can use any variety of plum or pluot for this recipe. (Plumcots, we see you too 👀.)

I usually eat plums straight from the basket before they ever make it into a recipe—but not this time! I managed to resist and it was oh so worth it.

The Plum Jam Filling

This easy stovetop plum jam is the star of the show. You’ll simmer fresh plums with:

  • Pure maple syrup
  • A touch of vanilla bean powder or extract
  • Ground cinnamon
  • A spoonful of tapioca flour to thicken

Cooking them down concentrates all that tart-sweet stone fruit flavor into a thick, jammy filling that caramelizes beautifully in the oven. Yes, you could layer raw plum slices in the bars, but trust me—this extra step is what makes them truly next-level.

These Plum Crumble Bars have a delicious oatmeal crust and crumble topping that's filled with a simple plum jam. These simple bars highlight one of the summer's best stone fruits in a delicious gluten-free and vegan dessert.

Oatmeal Crust & Crumble (One Dough, Two Jobs)

The same dough is used for the crust and the crumble, which keeps things simple. It’s hearty, nutty, and just sweet enough to complement the rich plum filling.

Here’s what goes into it:

  • Almond flour for tenderness
  • Coconut flour for structure and crunch
  • Old-fashioned rolled oats for texture
  • Cinnamon for cozy warmth
  • Maple syrup, coconut oil, and a touch of almond butter to bring it all together

You’ll press about two-thirds of the mixture into the pan to form the base, spread the jam layer, and then sprinkle the remaining mixture on top for a golden, buttery crumble.

These Plum Crumble Bars have a delicious oatmeal crust and crumble topping that's filled with a simple plum jam. These simple bars highlight one of the summer's best stone fruits in a delicious gluten-free and vegan dessert.

Recipe Tips & Substitutions

  • No coconut flour? Swap for a little extra almond flour, or use oat flour instead.
  • Need it nut-free? Try sunflower seed butter in the crust and sub the almond flour for a gluten-free oat flour blend.
  • Short on time? Use store-bought refined sugar-free plum jam in a pinch.
  • Want to mix it up? Add other stone fruits, such as nectarines or apricots, to the filling for a fun twist.

How to Store Plum Crumble Bars

These bars store super well, making them great for meal prep, lunchboxes, or a quick snack.

  • Room Temp: 1–2 days in an airtight container
  • Fridge: Up to 5 days
  • Freezer: Freeze in layers with parchment paper for up to 2 months

They’re just as tasty cold as they are warm, but you can reheat them in the oven or toaster oven to re-crisp the topping.

These Plum Crumble Bars have a delicious oatmeal crust and crumble topping that's filled with a simple plum jam. These simple bars highlight one of the summer's best stone fruits in a delicious gluten-free and vegan dessert.

FAQ

Can I use other stone fruit instead of plums?
Yes! This recipe works beautifully with apricots, nectarines, peaches, or pluots. A combo of stone fruits would be delicious too.

Do I need to peel the plums?
Nope—leave the skins on! They soften when cooked and add great color and flavor.

Can I make this recipe grain-free?
To go completely grain-free, skip the oats and add a little extra almond and coconut flour. You may need to adjust the moisture levels slightly.

Is the crust supposed to be soft or crispy?
The crust is tender with a light crispness, especially when freshly baked or reheated. For extra crunch, bake for a few extra minutes.

Want more stone fruit goodness?

These Plum Crumble Bars have a delicious oatmeal crust and crumble topping that's filled with a simple plum jam. These simple bars highlight one of the summer's best stone fruits in a delicious gluten-free and vegan dessert.
Rachel Conners

Plum Crumble Bars

4.84 from 6 reviews
These Plum Crumble Bars have a delicious oatmeal crust and crumble topping that’s filled with a simple plum jam. These simple bars highlight one of the summer’s best stone fruits in a delicious gluten-free and vegan dessert.
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Prep Time: 45 minutes
Cook Time: 25 minutes
Total Time: 1 hour 10 minutes
Servings: 16 bars

Ingredients
 

For the crust and crumble

For the plum filling

  • 3 cups fresh plums, pitted and chopped into small chunks (I used 5 plums)
  • 2 tablespoons maple syrup
  • 1 tablespoon tapioca flour
  • ¼ teaspoon vanilla bean powder or 1 teaspoon vanilla extract
  • ¼ teaspoon cinnamon

Instructions
 

  • Preheat oven to 350°F and line an 8×8-inch square pan with parchment paper. Grease with nonstick cooking spray.
  • In a mixing bowl, combine the almond flour, gluten-free rolled oats, coconut flour, and cinnamon; whisk to combine. Add the maple syrup, coconut oil, and almond butter. Stir until the dry ingredients are completely moistened and it sticks together but is still a little crumbly. Press 2/3 of the crust into the prepared pan, reserving the rest for the topping. Place the extra dough into the refrigerator.
  • Bake crust for 10 minutes and then set aside to cool.
  • While the crust bakes, add the plums to a saucepan over medium heat. Stir in the maple syrup, tapioca flour, vanilla bean powder, and cinnamon. Cook down the chopped plums for about 20 minutes or until they’re mostly broken down and reducing a little bit. Put in the blender or food processor and blitz for a few seconds to blend up the skins.
  • Return the blended plum mixture to the saucepan and cook for 15 minutes or until it cooks down into a thick paste. When you run a wooden spoon through the center, it should take a second before it floods back into the middle. When it’s reached that thicker consistency, pour and spread evenly over the baked crust.
  • Sprinkle the remaining crumble topping evenly over the top of the plum jam.
  • Bake for 25 to 30 minutes, or until the topping is a nice golden brown.
  • Let cool completely in the refrigerator before cutting into squares. Store in the refrigerator for 3-4 days or in the freezer for a few months.
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