Sunday, December 8, 2013

fruit crumb bars | recipe

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cranberry orange brown butter crumb bars
Take fruit filling of your choice and sandwiched it in between two layers of buttery shortbread-like cookie crust. The result: tiny pie bars.

The possibilities are endless. For the cookie, you can use ground oatmeal/oat flour, ground almonds, browned butter. Then, fill them with whatever is in season, blueberries, cranberries, blackberries, strawberry rhubarb (I can't wait to try this).

I first saw this recipe in many years ago on Smitten Kitchen. She adapted it from the original from All Recipes.
blueberry crumb bars
I made these in 2009

Since then, I've made them with brown sugar, granulated sugar, frozen berries, fresh berries, and most recently browned butter, cranberries, and ground oatmeal.

Let's first talk about sugar. Brown sugar (not raw or turbinado sugar) is granulated sugar with molasses added. More added molasses separates the light brown sugar from dark brown sugar. Molasses is a hygroscopic sugar meaning it attracts moisture making baked goods, like an oatmeal cookie, chewy.

blueberry crumb bars
brown sugar only on left, granulate sugar only on right
Thirty minutes in the oven was enough to dehydrate even the brown sugar bars and both brown sugar and granulated sugar bars were equally crisp. The bars baked with brown sugar were darker in color and tasted distinctly like brown sugar, which I thought was slightly distracting. As a result of this experiment, I would recommend sticking with granulated sugar for this recipe.

I usually make a half recipe but I still haven't found a good way around the half egg issue. I usually just end up cooking it in another recipe.

crumb bar cookie base
yields a 9 x 13 pan

3 cups or 15 ounces all-purpose flour
1 teaspoon baking powder
1/2 teaspoon table salt
1 cup granulated sugar
2 sticks or 8 ounces cold unsalted butter, cut into 1/2 inch cubes
1 large egg, beaten
1 teaspoon vanilla extract

substitute 1/2 cup or 2.5 ounces of flour for 1/2 cup of ground oatmeal or ground almonds
substitute butter for chilled browned butter

Preheat oven to 375 degrees F. Grease or line a 9 x 13 pan with parchment paper.

Prepare your fruit filling first (see below).

Combine flour, oatmeal or almond flour if using, baking powder, and salt in a bowl of a food processor. Pulse to combine ingredients.

Add cubes of cold butter. If using chilled brown butter, my guess is that it's probably chilled in a bowl and very hard to scrape out of said bowl. Either microwave it for 10 seconds or dip the bowl in a larger bowl filled with hot water until you can loosen the butter from the bowl. Then use a knife and roughly chop the butter into smaller chunks before adding it to the food processor. Pulse the butter with flour until the ingredients resemble coarse cornmeal.

Add the vanilla extract to the beaten egg and pour over the flour mixture. Continue to pulse until the dough starts to clump together. The pieces should range from the size pea to olive. If the mixture is still very dry and crumbly, try to pinch a bit of the dough with your thumb and two fingers, if the mixture doesn't stick, add one tablespoon of water and continue to pulse until the dough comes together.

Scatter a little more than half of the dough into the prepared pan. Spread your fruit filling (see below) evenly over the cookie base. Then scatter the remaining dough over the top.

Bake at 375 degrees F for 45 minutes for a 9 x 13 pan or about 30 minutes for an 8 x 8 pan or until the top is slightly browned. Cool then cut into 2 inch squares.

crumb bar fruit filling

fresh blueberry crumb bars 
4 cups blueberries
1/2 cup granulated sugar
juice from 1 lemon
zest from 1 lemon
4 teaspoons cornstarch

Mix in a large bowl and set aside.

frozen blueberry crumb bars
4 cups frozen blueberries
1/2 cup granulated sugar
juice from 1 lemon
zest from 1 lemon
4 teaspoons cornstarch

Empty bag of frozen blueberries onto a tray lined with two layers of paper towels. Wait 10 minutes for the outer layer of ice to melt. Then transfer the berries into a bowl and add the remaining ingredients and mix gently.

cranberry orange crumb bars
4 cups fresh cranberries (approximately 1 pound)
3/4 cup granulated sugar
2 tablespoons orange juice
1/2 teaspoon orange zest

In the bowl of a food processor, add all of the ingredients and pulse until the berries are coarsely chopped, a few whole berries are okay.

Transfer to a bowl and set aside to macerate.

strawberry rhubarb crumb bars
recipe coming in the spring

other berry crumb bars
follow the fresh blueberry recipe for fresh raspberries and blackberries. Do not substitute strawberries because they are too watery.


  1. That looks goood! I bet blackberries would be great also. :-)

    1. I agree, blackberries would be lovely.