Lemon-Blueberry Crumb bars

I made these for my summer fun party and they were a huge hit. I found the recipe in the latest edtion of the Kraft Food & Family Magazine. Here's the recipe:

1/2 cup butter
1 pkg (2-layer size) yellow cake mix
2 eggs, divided
2 tsp. zest and 3 Tbsp. juice form 1 lemon, divided
2 (8oz) packages cream cheese, softened
1/2 cup sugar
2 1/2 cups fresh blueberries

1. Pre-heat oven to 350 degrees.

2. Line 13X9 pan with foil, with ends extending over the sides. Spray with Pam.

3. Microwave butter in large microwaveable bowl on high 1 minute or until melted. Add cake mix, 1 egg, and 1 Tbsp. lemon juice. Beat with mixer until well blended. Press 2/3 of the mixture onto bottom of prepared pan.

4. Beat cream cheese and sugar with mixer until well blended. Add remaining egg, lemon juice, and zest; mix well. Pour over crust; top with berries.

5. Pinch small amounts of the remaining cake mixture and press lightly into the cream cheese layer.

6. Bake 48-50 minutes or until center is almost set. Cool completely. Refrigerate 1 hour. Use foil handles to lift from pan before cutting into bars. Keep refrigerated.