Step 1

Preheat the oven to 325 degrees F. Spray a 9x13 inch pan with nonstick spray.

Step 2

PREPARE THE SHORTBREAD: In a large bowl, use an electric mixer to combine the butter and sugars; beat until creamy. Add the vanilla and salt, and beat until well combined. Beat the flour into the butter mixture on low speed, just until a smooth dough forms. Divide the dough in half. Wrap one half in plastic wrap and refrigerate for 30 minutes or so. Press the other half of the dough into the bottom of the prepared pan to form the bottom crust. Bake the crust until it is just beginning to turn light brown around the edges, about 20 minutes. Remove the pan from the oven.

Step 3

ADD FILLING AND TOPPING: Place the jam into a bowl and stir very well until it is nice and smooth. Spread the jam evenly over the partially baked crust. Crumble the refrigerated shortbread dough over the jam to form a crumbled topping. Return the pan to the oven and continue baking until the topping is firm and crisp and golden in color, about 30 minutes. Transfer to a wire rack and let cool completely. Sprinkle lightly with powdered sugar before cutting into bars.