Mixed Berry Oat Squares

Great Harvest has some really yummy raspberry oat crumble bar thingies... they are so good. I wanted to find a copycat recipe, and came across a similar one in my new Whole Grain Baking cookbook (from King Arthur Flour). Some of the ingredients seemed a little weird to me, so I tweaked it slightly, and came up with this recipe. If you don't think about the butter and sugar in these, they're really healthy!! :D

CRUST:
3/4 cup butter
3/4 cup plus 2 T. packed brown sugar
1/2 tsp. salt
2 cups traditional whole wheat flour (hard red wheat)
1/3 cup all purpose flour
1/2 tsp. baking powder
1/4 cup orange juice
2 tsp. vanilla

FILLING:
6 cups frozen mixed berries (or berries of your choice, but makes sure they're the loose frozen berries, and not the ones frozen in syrup. This equals approximately 2 12-oz bags. Mine were from Fairview, Oregon. How cool is that?)
1 1/4 cup sugar
6 T. cornstarch
pinch of salt
1 T. butter
1 T. lemon juice
1 tsp. vanilla

TOPPING:
3/4 cup traditional whole wheat flour
2/3 cup regular (old-fashioned) rolled oats
1/2 cup packed brown sugar
1/4 tsp. baking powder
1/8 tsp. salt
1 T. orange juice
1/4 cup cold butter

Defrost berries slightly in microwave, or let them sit on the counter (dumped in a saucepan so you keep all their juices) for several hours. Preheat oven to 300. Spray 9x13 pan with Pam.

For the crust, beat butter, sugar and salt in a bowl till combined. Then add remaining ingredients and mix till combined. Press into pan and smooth the best you can. Prick all over with a fork. Bake for about 30 minutes, or just until it starts to brown. Take out of oven and turn oven up to 350.

For filling, stir together berries, sugar, cornstarch and salt in medium saucepan. Cook and stir over medium heat until mixture thickens and looses it's cloudyness (the cornstarch doesn't have to be completely dissolved-- just make sure it's shiny and thick). Remove from heat and stir in butter, vanilla and lemon juice. Spread over baked crust.

For the topping, combine all dry ingredients and mix well. Add orange juice and butter and use pastry blender to combine until crumbly. Sprinkle evenly over filling.

Bake for 35 minutes at 350, or until filling is bubbly and topping has browned. Cool overnight before cutting.

The recipe says cool overnight before cutting, and I don't know why, but I did and they were good. So whatever. :)

Also, I divided this among 2 8" square pans, and I had some leftover filling and topping. So if you halve the recipe, probably use a 9" square pan. 8" is a little small.