Blueberry Crumb Bars

It's blueberry season! I have a hard time passing up a good deal so I am stuck with a ton of blueberries. Since one person can only have so many smoothies I decided to bake something.
Muffins seemed too predictable, so I tried something new. These recipe would also work nicely with cherries, or cranberries!

With Andrew being away, I will have to bring these into work so I don't "accidentally" eat the entire pan.

For the crumb -

• 1 cup white sugar
• 1 teaspoon baking powder
• 3 cups all-purpose flour
• 1 cup cold unsalted butter
• 1 egg
• 1/4 teaspoon salt
• Zest of one lemon

For the filling -

• 4 1/2 cups fresh or frozen blueberries
• 1/2 cup white sugar
• Juice from one lemon
• 4 teaspoons cornstarch

1. Preheat the oven to 375 degrees F. Grease a 9×13 inch pan.

2. In a medium bowl, stir together 1 cup sugar, 3 cups flour, and baking powder. Mix in salt and lemon zest. Using your hands, incorporate the butter until it's a course meal. Use a fork or pastry cutter to mix in the egg. Press half of dough into the prepared pan.

3. In another bowl, combine blueberries, sugar, lemon juice, and cornstarch. sprinkle the blueberry mixture evenly over the crust. Crumble remaining dough over the berries.

4. Bake for 40 minutes, or until top is slightly brown. Cool completely before cutting into squares.
Serve chilled.