Mixed Berry Oat Shortbread Bars
These mixed berry oat shortbread bars are a sweet, buttery shortbread crust treat filled with a tangy berry sauce, that is ideal for both breakfast and dessert alike. Use any combination of berries you like to create the gooey, jammy center, sandwiched between the most irresistible oat shortbread crust and topping that makes these bars so divine.
Servings: 16 bars
Equipment
- Cutting board
- Sharp knife
- Mixing bowls
- Measuring cups
- Measuring spoons
- Mixing spoon/silicone scraper
- Hand mixer, stand mixer, or pastry fork/pastry whisk (I used a Danish pastry whisk, as seen in the images)
- 9x9 square baking pan (9x13 for thinner bars)
- Parchment paper
- Kitchen clips (to hold the parchment in place)
Ingredients
- 2 cups all-purpose flour
- 2 cups old fashioned oats
- 1-½ cups brown sugar packed
- 1 teaspoon baking powder
- 1 teaspoon vanilla extract
- ½ teaspoon salt
- 1 cup 2 sticks unsalted butter, cold
- 2 cups mixed fresh or frozen berries See notes for information about using frozen berries
- ¾ cup granulated white sugar
- 1 tablespoon corn starch
- Juice of half a lemon about 1 tablespoon
- Zest of 1 lemon about 1.5 teaspoons
Instructions
Prep and preheat
- Preheat your oven to 350 degrees F.
- Line a 9x9 square baking pan with parchment, allowing it to hang over the edges of the pan if possible, and clipping the sides to the edges as needed. Set aside.
Make the crust/topping
- Gather the ingredients needed.
- In a large mixing bowl, combine the flour, oats, brown sugar,baking powder, vanilla extract, and salt.
- Cut in the butter.
- Mix until crumbly.
- Press ⅔ of the oat mixture firmly into the bottom of your prepared baking pan. Reserve the remaining oat mixture.
Make the mixed berry filling
- In a large mixing bowl, toss together the berries, granulated white sugar, corn starch, lemon juice, and lemon zest until the berries are coated well.
- Use the edge of a mixing spoon or silicone scraper to gently macerate some of the berries, reducing any very large chunks.
- Spoon the berry mixture over the pressed oat crust layer in your baking pan.
Top the bars and bake
- Crumble the remaining oat mixture over the berry layer, sprinkling evenly from edge to edge.
- Bake for 45-50 minutes, until the crust is fully baked, the berry layer is bubbly, and the topping is golden brown.
- Allow to cool completely, then cut into squares and serve.
Notes
- Use any combination of berries you like. I used blackberries and raspberries. You could add or substitute sliced strawberries, blueberries, and/or black raspberries if desired.
- If needed, you can use frozen mixed berries. You may need to add a few extra minutes of baking time since the berry layer will be frozen before baking.
Do NOT thaw beforehand if using frozen berries. Your berry layer will be too juicy and may not set properly while baking. - As your berries sit in the bowl, the lemon juice will render the natural juices from the berries. Be sure to drain any excess juice before spreading the berries over the shortbread crust. This is why I also recommend mixing the oat shortbread mixture first, so as to avoid any excess sitting/sweating in the berry mixture.
- You don’t have to macerate the berries if you don’t want to. My blackberries were very large, so I wanted to get them cut up a bit and incorporate the pieces throughout my berry layer.
- Be sure to use old fashioned rolled oats, NOT quick-cooking or steel cut oats. If you use these, you will compromise on consistency and cooking time.
- You can use salted butter, but if you do this, skip the added salt.
- A 9x9 baking pan will yield 16 square bars, two inches in length/width/height. You can use a bigger pan, such as a 9x13, to make thinner bars.
- If you notice that your topping is browning too quickly in the oven, you can cover the pan with aluminum foil and return it to baking. Be very careful to avoid burns!
- Allow the bars to cool completely to room temperature before cutting and serving. They will fall apart easily if they aren’t cool, and will firm up upon cooling.
- Store leftovers covered at room temperature for up to 5 days, or in the fridge for a week.
- You can also wrap and freeze these bars for up to 2 months. Bring to room temperature before serving.