Blackberry Oatmeal Bars Recipe

I’m sharing my Blackberry Oatmeal Bars that tuck juicy fresh blackberries into buttery oat layers for an easy dessert full of homey flavor.

I love making Blackberry Oatmeal Bars because they sneak fresh blackberries into an oat-forward crumb that’s somehow both simple and unexpected. The chew from old fashioned rolled oats gives each bite real texture, and people always ask what that little fruity pop is.

I call it a Blackberry Dessert at family get togethers, though I never tell them how easy it is. It sits between rustic and clever, the kind of thing you bring to a porch where no ones in a hurry.

I always end up testing leftovers at midnight, and yep, it still surprises me.

Ingredients

• Oats add chewy texture, fiber and slow carbs, makes bars hearty not too sugary.
• Flour gives structure and tender crumb, adds carbs so they hold together.
• Brown sugar adds molasses warmth and sweetness, keeps filling caramel like sometimes.
• Butter brings rich flavor, moisture and crisp edges when baked, it browns nice.
• Blackberries give tart juicy burst, lots of vitamin C and fiber, stains fingers.
• Cornstarch thickens the filling so it sets up, no runny mess.
• Lemon adds brightness and balance, cuts sweetness and wakes the fruit flavor.
• Vanilla deepens aroma, rounds flavors and makes everything taste homelier.

Ingredient Quantities

• 2 cups old fashioned rolled oats
• 1 1/2 cups all purpose flour
• 1 cup packed light brown sugar
• 1 teaspoon baking powder
• 1/2 teaspoon salt
• 1 cup unsalted butter 2 sticks
• 1 teaspoon vanilla extract
• 3 cups fresh blackberries
• 1/3 cup granulated sugar
• 2 tablespoons cornstarch
• 1 tablespoon fresh lemon juice
• pinch salt for filling
• 1/4 teaspoon ground cinnamon optional

How to Make this

1. Preheat oven to 350F and line an 8×8 inch baking pan with parchment leaving an overhang so you can lift the bars out later.

2. In a bowl stir together 2 cups old fashioned rolled oats, 1 1/2 cups all purpose flour, 1 cup packed light brown sugar, 1 teaspoon baking powder, 1/2 teaspoon salt and the optional 1/4 teaspoon ground cinnamon if you want that warm note.

3. Cut 1 cup cold unsalted butter (2 sticks) into small cubes and work it into the dry mix until crumbly and pea sized (use a food processor, pastry cutter, or grate the butter on a box grater for a faster hack). Stir in 1 teaspoon vanilla. Reserve about one third of the crumb mixture for the topping and press the rest firmly into the prepared pan.

4. Par-bake the pressed crust 12 to 15 minutes, until it’s just set and starting to color at the edges; this keeps the bottom from getting soggy.

5. While the crust par-bakes, make the filling: in a bowl gently toss 3 cups fresh blackberries with 1/3 cup granulated sugar, 2 tablespoons cornstarch, 1 tablespoon fresh lemon juice and a pinch of salt. If some berries are big, crush a few with a fork so the filling runs a bit.

6. Spread the blackberry mixture evenly over the warm par-baked crust.

7. Sprinkle the reserved oat crumb evenly over the berries, lightly press so it adheres but dont compact it too much.

8. Bake 30 to 35 minutes more, until the topping is golden and the filling is bubbling at the edges. If the top browns too fast tent loosely with foil for the last 10 minutes.

9. Let the bars cool completely (at least
1.5 to 2 hours) so the filling sets, then lift out with the parchment and cut into squares. Tip: chill briefly before slicing and use a sharp knife wiped clean between cuts for neat bars; store in fridge up to 4 days.

Equipment Needed

1. Oven, set to 350F
2. 8×8 inch baking pan lined with parchment leaving an overhang so you can lift the bars out later
3. Parchment paper (and kitchen scissors to trim)
4. Mixing bowls, at least one large for the dry mix and one medium for the blackberry filling
5. Measuring cups and spoons
6. Pastry cutter or food processor or box grater to cut/grate the cold butter (pick one)
7. Rubber spatula or wooden spoon for stirring and pressing the crust, plus a fork to crush a few berries
8. Wire cooling rack and a sharp knife for slicing (wipe the knife between cuts)

FAQ

Blackberry Oatmeal Bars Recipe Substitutions and Variations

• 1 cup unsalted butter: swap with 1 cup solid coconut oil or 1 cup vegan butter (use same measure). Coconut oil gives a faint coconut taste and the bars will be firmer when chilled.
• 1 1/2 cups all purpose flour: use 1 1/2 cups whole wheat pastry flour for a nuttier, slightly denser bar, or 1 1/2 cups gluten free 1-to-1 baking flour if you need gluten free.
• 3 cups fresh blackberries: use 3 cups frozen berries (keep them mostly frozen or just slightly thawed) and add 1 to 2 extra tablespoons cornstarch since frozen berries release more juice, or try mixed berries for a different flavor.
• 1 cup packed light brown sugar: substitute with 1 cup granulated sugar plus 1 tablespoon molasses (stir until combined) or use coconut sugar 1:1 for a less sweet, caramel-y note.

Pro Tips

– Sprinkle a thin layer of almond flour, ground oats or very finely crushed graham crackers over the pressed crust before adding the berries, it soaks up extra juice so the bottom wont get mushy.

– For brighter, deeper flavor fold in a tablespoon of good seedless blackberry or apricot jam plus a little lemon zest. The jam helps the filling set and the zest makes the whole thing pop.

– Toast the oats for the crumb in a dry skillet until they smell nutty, then let them cool before mixing. Youll notice a richer, more toasty flavor compared to raw oats.

– For neat squares chill the bars until firm, run a sharp knife under hot water then wipe it clean between cuts or use unflavored dental floss to slice straight lines. Bars also freeze great wrapped tight for up to two months.