Plum Bars with Crumble Topping

Looking for creative ways to use up some delicious summer stone fruit? These Plum Crumble Bars are totally decadent, easy to make, gluten-free, and low in carbs! Bursting with gooey plum goodness, a buttery crust, and a streusel like topping, they're hard to resist!

Disclosure: This post is brought to you in partnership with our friends at Bob’s Red Mill. We used their superfine almond flour, coconut flour, and xanthan gum to make these drool-worthy bars! We love using Bob’s Red Mill products to craft the most delicious baked goods. Thank you for supporting the brands that help to bring fresh new content to A Full Living!

If you're looking for an easy gluten-free recipe that's sure to delight, you don't want to miss out on these bars! Start with a delicious shortbread crust with a hint of lemon, then fill the bars with a jammy, plum filling. Top with a yummy crumbly topping made with almond flour and some pecans, and you're in business.

Looking for more delicious summer treats? Try these white chocolate raspberry cookies, these brownie blondie bars, or this keto carrot cake!

Jump to:

• ❤️Why we love this recipe
• 🌸Ingredients
• ✏️Ingredient notes
• 📖Instructions
• 🥣How to substitute for almond flour
• 💭Frequently asked questions
• 🧁More recipes to try
• 🥣Storage
• 🌟Leave a 5-star review!
• 📖 Recipe
• 💬 Community

❤️Why we love this recipe

• Naturally gluten free - These bars are made with almond flour, coconut flour, and xanthan gum to thicken, so there's absolutely no gluten!
• Low carb & sugar free option - Almond flour & coconut flour are not only gluten free, but they're also very low in carbohydrates as well! We also use a sugar substitute to make these bars with only 8 net carbs per serving. You could use regular sugar if you prefer.
• Bursting with summer flavor - The perfect use for bright, sweet plums. The color alone is worth swooning over, but you'll love the bright, sweet, and zippy flavor of these bars. A juicy plum filling with a buttery crust and a crumb topping, this dessert will become your new summer favorite!

🌸Ingredients

Here are the ingredients you'll need for this recipe. You can find the full quantities and nutritional information in the recipe card.

✏️Ingredient notes

• Bob's Red Mill super fine almond flour & coconut flour - Our preferred gluten free and low carb flour. Bob’s Red Mill Super-Fine Almond Flour is just that, super finely ground, so you’re not going to get a bunch of grainy bits. We also use a bit of Bob's Red Mill coconut flour for the perfect balance in texture. Make sure you don't substitute the almond flour for coconut flour however. Coconut flour is very drying, and is not a 1:1 substitute for almond flour.
• Sugar free sweetener - Something granular to replace regular granulated sugar will be your best bet here. Brown sugar erythritol also works great in place of light brown sugar if you like a little bit of a molasses like taste in your bars. We prefer to use regular granular or brown erythritol, as it bulks, bakes ands tastes like sugar. Also, sweeten the filling to taste here. Not all plums are equal in sweetness!
• Unsalted butter - Make sure it's very cold! We like to cut it into small bits or grate it from frozen into the dry ingredients to make the crust. Butter is also used in the plum filling.
• Kosher salt - A pinch of salt is always used in our recipes. A bit of salt highlights sweetness in these delicious bars.
• Xanthan gum -  We love Bob’s Red Mill Xanthan Gum for binding our gluten free baked goods. Plus, it's necessary to thicken the plum filling.
• Ground cinnamon - Optional, but pairs nicely with the plum flavor.
• Lemon juice & zest - We add a bit of lemon zest to the crust, as well as to the filling. Fresh squeezed lemon juice is also added to the plum filling.
• Fresh ripe plums - Make sure they're ripe, but not mushy. You want them to be firm to the touch but give a little when you press them. No need to do anything fancy with the plums. Just cut them in half, get rid of the pit, and cut them into small bite sized chunks.
• Pecans - Technically option, we love a little bit of crunch in our crumble topping! Almonds would also make a great choice here. If you prefer, you can leave the nuts out.

📖Instructions

🔪Prep work

• Lightly grease the bottom of a 9x9 square baking pan, then line with enough parchment to completely cover the sides. This allows the bars to release easily.
• Preheat the oven to 350 degrees Fahrenheit.

Make the crust & crumble

In a large bowl, combine almond flour, coconut flour, some of the sweetener, lemon zest, xanthan gum, and kosher salt with most of the cold butter. Work the butter into the dry ingredients by hand with a pastry cutter, or use a food processor if you prefer.

Pro tip: You don't want to work the dough too much, you just want the mixture to look like wet sand. You can use your hands at this point to shape the dough into a ball.

Cut the ball of dough in half. Set half aside to press into the bottom of your pan. Add the pecans to the remaining half, mixing it together with your finger tips, until the mixture forms streusel-like crumbs. This will be your topping. Set aside.

Bake the crust

Press half of the dough into the bottom of your pan. Use a measuring cup to make sure it's in as much of an even layer as possible.

Bake the crust for about 15-17 minutes, until it's golden brown. Set aside and allow to cool for about 15-20 minutes before moving on.

Make the plum filling

In a sauce pan, add plums, lemon juice, remaining butter, lemon zest, sweetener, cinnamon, and salt. Bring to a boil, then reduce to medium-low heat to allow the plums to soften, break down and thicken for about 15 minutes.

Adjust sweetness and flavors while tasting as you go.

After the mixture has began to thicken now that some water has evaporated off, add some xanthan gum in small bits at a time, whisking continuously to avoid clumping. Stir in the vanilla extract at this time as well.

Allow the mixture to simmer for about 20 more minutes. You want to cook out most of the moisture.

Pro tip: If you want an extra silky smooth filling, feel free to use a blender or immersion blender to puree the plum mixture so there are no chunks.

Assemble & bake the bars

Add the jammy plum filling to the cooked crust, spreading it evenly. Add your crumb mixture topping, and lightly press it into the filling to adhere. Bake for an additional 22-27 minutes, until the top is golden brown.

Allow the bars to cool completely at room temperature before cutting. This will take about 2 hours. (We know, it's long!! Be patient!)

Cut into 12 equal pieces with a sharp knife for easy cutting. Serve plain, or with some low carb ice cream or whipped cream if you want! We found some beautiful edible flowers at the farmer's market and we couldn't resist.

🥣How to substitute for almond flour

• As we mentioned, coconut flour is not a 1:1 substitute for almond flour, so unfortunately that won't work here.
• If you want to use all purpose flour in place of almond flour and coconut flour, this can probably be done by using an equal amount of all purpose flour to the weight of both flours combined. If using AP flour, you can skip the xanthan gum, as gluten causes a binding reaction on its own.
• A better replacement would be Bob's Red Mill 1-to-1 gluten free flour. It's not low carb (if you are concerned about that) but it's specially formulated to replace regular flours in any recipe. In this blend, xanthan gum is already added, so skip adding it.

💭Frequently asked questions

🧁More recipes to try

• Blood Orange Chocolate Cupcakes (Low Carb, Gluten Free)
• Cheesy Gluten Free Garlic Breadsticks
• Fluffy Keto Coconut Flour Pancakes

This recipe was adapted from our healthy apple crumble bars recipe and pumpkin pie crumble bars. We do test each recipe individually, as each fruit or filling has its own specific needs, sweetness levels, moisture levels, etc.

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🥣Storage

Store any leftovers in an airtight container at room temperature for 2-3 days, then transfer to the fridge. These bars will keep for about 1 week.

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📖 Recipe