Blueberry Lattice Bars (Maine)

Maine has an annual blueberry festival, this recipe won a blue ribbon one year.

1⅓ cups butter, softened
⅔ cup sugar
¼ tsp. sea salt
1 large egg, room temperature
½ tsp. pure vanilla extract
3¾ cups all-purpose flour, unbleached

Filling:
3 cups fresh or frozen blueberries
1 cup sugar
3 Tbsp. cornstarch

Cream butter, sugar and sea salt until light and fluffy; beat in egg and vanilla. Gradually beat in flour. Divide dough in half; shape each into a 1” thick rectangle. Wrap and refrigerate 2 hours or overnight.

Preheat oven to 375°F (190°C/170°C fan, Gas Mark 5). Grease a 9x13" baking pan.

Place blueberries, sugar and cornstarch in a small saucepan. Bring to a boil over medium heat, stirring frequently; cook and stir until thickened, about 2 minutes. Cool slightly.

Roll each portion of dough between two sheets of plastic wrap into a 10x14” rectangle. Place rectangles on separate baking sheets; freeze until firm, 5-10 minutes. Place one rectangle in the prepared baking pan, pressing onto bottom and about ½” up the sides. Add filling.

Cut remaining rectangle into ½” strips; freeze 5-10 minutes to firm. Arrange strips over filling in crisscross fashion. If desired, press edges with a fork to seal strips. Bake until top crust is golden brown, 30-35 minutes. Cool on a wire rack. Cut into bars.

Makes 2 dozen.