Curd Shortbread Sandwiches

½    cup    packed light brown sugar
12   Tbs.   butter, room  temperature
1 ½ cups   all- purpose flour
¾    cup    Ms. Earle’s lemon or key  lime curd

Preheat the oven to 325 F. Coat a 7-by-11 inch baking dish with cooking spray. Press a piece of plastic wrap over the bottom of the dish, letting the ends hang over the sides; smooth out any wrinkles.
In a medium bowl, combine the brown sugar and butter. Use an electric mixer on medium speed to beat until light and fluffy, about 1 minute.
On low speed, beat in the flour until the mixture is well blended and holds together when pressed. Gather the dough in to a ball. Divide even layer over the bottom of the prepared dish. Grab the edges of the plastic wrap and lift the rectangle of dough out of the dish. Set aside. Press the remaining dough over the bottom of the dish in an even layer. Spread the Ms. Earle’s lemon or key lime curd on top. Invert the reserved first half of the dough directly on to the filling. Peel away the plastic wrap.
Bake for 35-45 minutes, or until golden. Transfer the dish to a wire rack and cool completely, about 2 hours. Cut into 12 rectangles.