This is our whole-wheat shortbread with tons of fruit on top and a whole lot of crumble, my idea of pure heaven. These would also be great with cranberries, sautéed apples, sautéed peaches, or sour cherries. But blackberries and blueberries are our traditional combination.
The best way to enjoy these is simply with a tall glass of milk. Or, if you want to take it to the next level, spike your milk. I can’t imagine a better cure for a sleepless night.
It’s key to slice the bars the moment they emerge from the oven. If you let them cool at all, they’ll be too crumbly and you’ll end up with a big ol’ mess instead of beautiful, clean-looking squares.
Recipe: Black and Blue Oat Bars
Yields: 16 bars
1 cup + 2 tbsp/255 g unsalted butter, cubed, at room temperature
⅓ cup/65 g granulated sugar
½ tsp kosher salt
1⅓ cups/170 g all-purpose flour
¾ cup/95 g whole-wheat flour
⅔ cup/85 g cornstarch
1 cup + 2 tbsp/55 g rolled oats
½ cup/60 g whole-wheat flour
6 tbsp/85 g unsalted butter, cubed, at room temperature
5 tbsp/70 g brown sugar
1 tbsp honey
½ tsp kosher salt
5 cups/750 g blackberries and blueberries
1 tbsp cornstarch
½ cup + 2 tbsp/130 g granulated sugar
1 tbsp water
¼ tsp kosher salt
Grease an 8-in/20-cm square baking pan.
To make the crust: Cream the butter, granulated sugar, and salt in a stand mixer fitted with the paddle attachment until fluffy, 1 to 2 minutes. Add the all-purpose flour, whole-wheat flour, and cornstarch. Mix cautiously, just until combined.
Press the dough into the prepared pan, distributing it evenly. Refrigerate for at least 30 minutes. Preheat your oven to 350°F/180°C.
Meanwhile, to make the crumble: Combine the oats, whole-wheat flour, butter, brown sugar, honey, and salt in a bowl and blend with your fingertips until homogenous. Set aside in the refrigerator until needed.
Bake the crust until golden, about 35 minutes.
When the crust nears readiness, make the filling: Toss together the berries, cornstarch, granulated sugar, water, and salt to combine.
Remove the crust from the oven and, immediately, while hot, fill it with the berry mixture and top with the crumble. Return it to the oven to continue baking until the filling bubbles and the crumble is deeply browned, about 1 hour longer.
While it’s hot, quickly slice into squares. I like to cut sixteen squares, which is four by four, but you can go with any size or shape you like— just as long as you cut them right away. Allow to cool completely before removing the squares from the pan. The best way is to run a knife through the original cuts a second time, then pry the squares out with a small spatula. Once you snag the first one, it gets easier.
These keep beautifully, tightly wrapped, at room temperature, for up to 3 days.