These berry crumble bars are made with a mixture of blueberries and raspberries but the most successful tweak that I made to the recipe was to replace part of the flour with graham cracker crumbs.
The graham cracker crumbs add a lot of extra flavor to the crust and topping and help the bars keep a bit of crispiness in their crumble even after being refrigerated.
Another step that I added is a favorite trick I picked up from a daring baker member: grate chilled butter and then freeze the grated butter. Whenever a recipe calls for a pastry cutter or to cut the butter into the flour I just grate the butter up and freeze it. It makes it really easy to work into the flour without melting the butter and it creates a great texture.
For this recipe the grated butter is worked into the four (I just used my hands) until the mixture is well combined and crumbly with no bits of butter left showing. It won't be like a dough, it looks more like a big bowl of floury crumbs
I made a big batch of these to take to the farm but only about half the bars made it there because the other half of the batch became after-bar snacks and breakfast. Putting the bars together took no time at all and we were rewarded with buttery, crispy-on-the-outside, soft-and-juicy-on-the-inside deliciousness.
I even started looking websites so see how expensive bigger freezers are because if I want to make these during the winter I'm going to have to start freezing batches of berries asap.
Berry Crumble Bars
1 cup white sugar
1 tsp baking powder
2 & 1/3 cups all purpose flour
2/3 cup graham cracker crumbs
1/4 tsp salt
1 cup chilled (not frozen) unsalted butter (2 sticks)
zest and juice of one lemon
3 cups fresh blueberries (I heaped my cups full)
1 heaping cup of raspberries
1/2 cup white sugar
4 tsp cornstarch
1. Grate the butter with a cheese grater and place in the freezer to chill. Preheat oven to 375F
2. In a medium bowl whisk together the 1 cup sugar, baking powder,the flour, graham cracker crumbs, salt, and lemon zest. Using a fork, pastry cutter, or your hands work the egg and the grated butter into the other ingredients until they come together to form a crumbly mixture
3. Grease a 9x 13 pan and pat half of the crumb mixture on the bottom of it
4. In another bowl stir together the berries, sugar, corn starch, and lemon juice. Gently spread evenly in the pan
5. Sprinkle the remaining crumb mixture on top of the berries
6.Bake in the preheated oven for 45 minutes or until top is slightly brown. Let the bars cool completely before cutting. These keep very well covered in the fridge