Cinnamon Blueberry Crumble Bars

Awhile back King Soopers was having a great deal on blueberries so I snatched up several 18 oz. containers... several as in 10, I believe. We ate some; I froze 2 quart size bags worth; I made blueberry muffins; and I also made these bars! They were really terrific. I liked the added texture of the oatmeal they called for. Here's the recipe:

Cinnamon Blueberry Crumble Bars
**from the Cake Mix Doctor 

Ingredients: 
1 pkg. plain yellow cake mix
1 c. (2 sticks) butter, melted
1 c. old-fashioned oatmeal
1/2 c. packed light brown sugar
2 lg. eggs
1 t. ground cinnamon
2 c. fresh blueberries, rinsed and drained
1/2 c. granulated sugar

To Make: 
Preheat the oven to 350*. Set aside an ungreased 9x13" baking pan. Place the cake mix, melted butter, oatmeal, brown sugar, eggs, and cinnamon in a large mixing bowl. Blend with an electric mixer on low speed for 1 to 1 1/2 minutes. Stop the machine and scrape down the sides of the bowl with a rubber spatula. The mixture will be thick. Reserve 1 1/2 cups for the topping. Transfer the remaining crust mixture to the pan. Using your fingertips, press the mixture evenly over the bottom of the pan so that it reaches all sides. For the filling, place the blueberries and granulated sugar in a small bowl and stir to combine. Pour the blueberries onto the crust, and spread with a spoon so that the berries are evenly distributed. Pinch off pieces of the reserved crust mixture and scatter them over the filling. Place the pan in the oven. Bake the cake until it is light brown and bubbling, 40-45 minutes. Remove the pan from the oven and place it on a wire rack to cool, 30 minutes. Cut the cake into 24 bars.
**Store these bars, covered in plastic wrap at room temperature for up to 3 days or in the refrigerator for up to 1 week (We did this. They were good cold.). Or freeze them, wrapped in aluminum foil, for up to 6 months. Thaw the bars overnight in the refrigerator before serving.

To life... full of fresh, summer blueberries!