Fresh Blackberry-Lemon Crumb Bars
- Preheat oven to 350° ; position oven rack in middle of oven; spray the bottom only of an 13 x 9 inch metal baking pan with nonstick cooking spray.
- In a big bowl, add the cake mix, butter, and egg; blend with an electric mixer set on low speed until all dry ingredients are moistened and mixture is well blended and crumbly.
- Press half of mixture evenly into bottom of prepared pan; bake 15 minutes.
- Meanwhile, in another bowl, whisk together lemon zest and condensed milk with the lemon juice; stir until blended.
- Place blackberries evenly over surface of partially baked crust; pour lemon mixture over blackberries evenly as possible; sprinkle with reserved crumb mixture.
- Bake 20-24 minutes or until topping is golden brown.
- Transfer to wire rack and cool completely.
- Cut into bars; store in refrigerator.