Blackberry Bars are made with sweet and tangy summer blackberries and an oat butter crumble. It’s an easy and delicious summer treat perfect for any occasion.
Fruit bars make for some of my favorite summer desserts. They are best with seasonal fruit, which can be mixed and matched for a variety of flavors. Blackberries are a great option for fruit bars but also for pies, tarts, and cakes. When ripe, blackberries have a delicious sweet and tangy flavor that makes them perfect for snacking on, but I also love transforming them into a simple filling perfect for these summer bars.
Blackberries are tossed with a bit of lemon, sugar, and cornstarch and sandwiched together between two layers of oat crumble. They’re baked to perfection and pair well with homemade vanilla ice cream for a refreshing treat. You can even serve these bars as a breakfast treat.
Before you begin
Take out the following baking equipment.
Digital kitchen scale
9 x 9-inch baking pan
Read the recipe through from start to finish.
Oats are an essential ingredient in the crumb crust and topping. Use old-fashioned oats when possible as they are larger and add more texture than quick-cooking oats, which become too fine in the food processor.
Use unsalted butter, as you are better able to control the amount of salt in a recipe. It’s essential to use cold butter so that you can produce a crumbly topping as opposed to a cookie dough-like texture.
When possible, use seasonal blackberries as they will yield the best flavor. If not in season, use frozen blackberries. However, frozen berries have higher water content and will require a greater amount of thickening agent.
Cornstarch is the thickening agent used in this blackberry filling. It’s added directly into the mixture and does not need to be premixed with a liquid. For it to do its job, wait until the filling is bubbling before removing your pan from the oven.
How to select the best fresh blackberries
Typically the peak blackberry season is from June through August. Here are tips for selecting the best berries.
- Buy local and in-season. The closer to home that berries are picked, the more likely they are picked when ripe. When berries have to travel a long way before reaching the consumer, they are picked before ripen and have less flavor. Once picked, blackberries do not continue to ripen.
- Select blackberries. Select berries that are dry, plump, firm, and deep purple/black. Avoid berries that are crushed and have bruising.
- Storing. Store in the refrigerator for up to 3 days.
How to make blackberry bars
Make the oat crumble. In a large bowl, whisk together the flour, oats, brown sugar, cinnamon, nutmeg, and salt. Use a pastry blender to cut the cold butter into the mixture until it resembles a coarse meal.
Mix filling. Combine the blackberries, sugar, cornstarch, lemon juice, and lemon zest in a medium bowl. Gently mix everything until evenly combined. Careful not to crush the berries.
Divide the crumble. Divide the crumble mixture into two and transfer one half to your baking pan. Press oat mixture evenly into the bottom of the pan.
Add filling. Pour the blackberry mixture over the crust and spread evenly. Crumble the remaining oat mixture over the top of the blackberry layer.
Bake. Bake for 30-35 minutes or until the blackberries are bubbling and the topping is slightly golden brown. Transfer to a cooling rack and cool to room temperature.
These bars are best stored in an airtight container in the refrigerator for up to one week. The cold temperature will keep the texture of these bars intact. You can store these bars in the freezer for up to 3 months. Individually wrap each bar tightly with plastic wrap and place the bars in a freezer-safe container or wrap with aluminum foil. To serve, allow the bars to thaw overnight in the refrigerator.
Tips and takeaways
- A pastry blender is your best friend for making the crust and crumb topping. It’s a tool that helps you easily cut the butter into your mixture.
- Once your blackberry bars come to room temperature after being baked, refrigerate for 1 hour or until chilled before cutting. Doing this will help solidify your filling so your bars can have a clean cut and not fall apart.
- For added texture and flavor, add up to 3/4 cup unsweetened coconut to your crust and crumb topping.
If you love fruit bars, try these other recipes…
Make sure to tag me @thesweetoccasion on Instagram and leave me a review below if you make these Blackberry Bars. I’d love to see your creations and read your feedback. And if you would like to make this recipe later, be sure to pin this recipe using the button on any of these images. Let’s make every occasion a sweet occasion!Print
Blackberry bars made with sweet and tangy summer blackberries and an oat butter crumble. An easy and delicious summer treat.
For the crust and crumb topping
- 280 g (2 cups) all-purpose flour
- 100 g (1 cup) old-fashioned oats
- 165 (3/4 cups) packed light brown sugar
- 4 g (2 teaspoons) cinnamon
- 2.8 g (1/2 teaspoon) salt
- 0.7 g (1/4 teaspoon) nutmeg
- 226 g (1 cup) cold butter, cubed
For the blackberry filling
- 340 g (12 oz) fresh blackberries
- 12 g (1 tablespoon) granulated sugar
- 6.3 g (3 tablespoons) cornstarch
- 15 g (1 teaspoon) fresh lemon juice
- Zest from 1 lemon
- Preheat oven to 350°F/177°C. Line a 9×9-inch baking pan with parchment paper so that it hangs over the sides. Set aside.
For the crust and crumb
- In a large bowl, whisk together flour, oats, brown sugar, cinnamon, nutmeg, and salt. Using a pastry blender, cut cold butter into the mixture until it resembles a coarse meal.
For the filling.
- In a medium bowl, combine blackberries, sugar, cornstarch, lemon juice, and lemon zest.
- Divide your crust mixture into two. Transfer one half to prepared baking pan and press evenly into the bottom of the pan. Pour blackberry mixture on top and spread evenly. Crumble remaining half of your oat mixture on top of the blackberry layer.
- Bake in preheated oven for 30-35 minutes, or until the blackberries are bubbling. Transfer to a cooling rack and cool until room temperature. Refrigerate for at least 1 hour before cutting and serving.
Make-ahead: You can make the crust and topping up to 3 days in advance and store it in the refrigerator. You can also store it in a freezer-safe container or bag in the freezer for up to 3 months.
Storing: Store in an airtight container in the refrigerator for up to 1 week. You can also wrap these bars individually and store them in a freezer-safe container in the freezer for up to 3 months. Allow the bars to thaw in the refrigerator overnight.
Keywords: blackberry bars, blackberries, bars