Mixed Berry Streusel Bars

Recipe Adapted from Williams-Sonoma

Ingredients

For the Shortbread crust:

• 14 Tbs. (1 3/4 sticks) unsalted butter, at room temperature, plus more for greasing
• 1 3/4 cups, plus 2 Tbs. all-purpose flour
• 1/4 cup, plus 1 Tbs. granulated sugar
• 1/4 cup, plus 1 Tbs. firmly packed light brown sugar
• 1/4 tsp. kosher salt
• 1 tsp. vanilla extract

For Filling

• 2 cups fresh blueberries or blackberries
• 2 cups fresh raspberries
• 1 tsp. grated lemon zest
• 1 Tbs. fresh lemon juice
• 1/2 tsp. almond extract
• 3/4 cup (6 oz./185 g) granulated sugar
• 3 Tbs. cornstarch
• 1/4 tsp. kosher salt

For Streusel Topping

• 1/2 cup, plus 2 Tbs. all-purpose flour
• 1/2 cup, firmly packed light brown sugar
• 1/4 tsp. kosher salt
• 3 Tbs. unsalted butter, melted
• 1/4 tsp. almond extract
• 2 Tbs. chopped raw almonds

Directions

For the Shortbread Crust

Preheat an oven to 350°F (180°C). Butter a 9-by-13-inch (23-by-33-cm) baking dish.

In the bowl of an electric mixer, beat the butter on medium speed until smooth, about 30 seconds. Stop the mixer and scrape down the sides of the bowl. Add the flour, granulated sugar, brown sugar, salt and vanilla and beat on medium speed until the mixture is crumbly, about 30 seconds.

Transfer the dough to the prepared baking dish and using damp hands, gently press in an even layer into the bottom of the pan. Using a fork, prick the dough in several places. Bake until the crust is light golden brown, about 20 minutes. Transfer the dish to a wire rack and let cool completely. Increase the oven temperature to 375°F.

For the Filling

in a large bowl, combine the berries, lemon zest, lemon juice and almond extract and toss to coat. In a small bowl, stir together the granulated sugar, cornstarch and salt. Sprinkle the sugar mixture over the berries and toss to distribute evenly. Transfer to the cooled crust and spread in an even layer. 

For the Streusel

in a medium bowl, whisk together the flour, brown sugar and salt. Add the melted butter and almond extract and stir until the mixture is crumbly, with some large chunks remaining. Stir in the almonds. Sprinkle the streusel over the blueberries. Bake until the filling is thick and bubbling and the streusel is golden brown, about 25 minutes.

Transfer the baking dish to a wire rack and let cool completely, about 1 hour. Cut into squares and serve.