Line an 8X8 baking pan with aluminum foil, allowing the foil to extend a couple of inches on two opposing side. Spray with nonstick cooking spray
Make the crust by adding to the bowl of a food processor the flour (1 1/2 cups), sugar (3/4 cup), and salt (1/8 teaspoon). Pulse for about 30 seconds to combine ingredients. Add the cubed cold butter (3/4 cup) and pulse until the butter pieces are about the size of peas. Remove 3/4 cup of the mixture to use as a topping and set aside until needed. Pour the rest of the crumb mixture into the prepared pan and press into the pan. Bake for 12-15 minutes or until the edges begin to turn golden. Cool completely.
Make the filling by mixing together, in a medium bowl, the eggs (2), sugar (1 cup), sour cream (1/2 cup), flour (1/4 cup), and salt (pinch) until well combined. Spread the berries in a single layer on the cooled crust. Spoon the filling batter over the berries (16 ounces).
Evenly spread the reserved crumb mixture on top of the filling. Bake for 45-55 minutes, or until the filling is just beginning to turn golden and is set. Cool bars completely on a baking rack then refrigerate if desired.
Notes
The top on your blackberry pie bars won’t turn dark brown but that is not indicative of doneness. I’ve included a photo of the top of the bars in the baking pan so you can get an idea for the slight browning/goldening that occurs.
Be sure to let your cookie bars setfor at least an hour before slicing them, it’ll give you a cleaner cut. I like eating mine cold, so I leave them in the fridge for a couple of hours before serving.
The recipe can be doubled and made in a 9X13 inch pan. Your yield will obviously depend on the size you cut the bars into. I like to cut them into 16 pieces.
When making the shortbread crust, keep your butter really cold. It’ll give it the proper consistencyas it cooks in the oven.
You can also use frozen blackberries if you don’t have access to fresh. Just be sure to defrost and drain them well beforehand or you’ll have unwanted moisture in your filling.