the problem with living in a house with just two people is that if you open a container of dessert, say, blueberry oat pecan crumble bars, and notice that the quantity of the dessert has been reduced by half over the course of 24 hours, and you ask the only other person who lives in the house if he ate any of the bars and he says no, then you are forced to accept the discomforting idea that someone has snuck in off the street to eat dessert out of your fridge, without leaving a trace or taking anything (else) of value.
and that was the first version of these blueberry oat pecan crumble bars, before i perfected the recipe! i can only imagine how much more i, i mean, this dessert thief might have eaten, had the first version of the “bars” not required a spoon or fork to scoop up all of the loose crumbs that refused to stay attached to the top of the bars.
luckily in subsequent batches of the bars, i figured out how to get the crumble top to not be *quite* so crumbly (i feel sure there must be some french phrase that translates as, “just add more fat and all of your problems will be solved”).
ok, have i convinced you yet that you need to make these, stat, before all the blueberries are gone (though honestly i think good frozen blueberries would also work)? how about if i mention that they have a nice pecan flavor that complements the blueberries in the most perfect way? or if i tell you how these prefer to be stored in the refrigerator and keep well for several days? barring the entrance of any dessert thieves, of course…
hopefully that’s sufficiently persuasive, because those tiny wild blueberries aren’t going to stick around forever (sadly), especially since i heard a rumor that fall is on the way. until then, these. make them. please and thank you.
ps – dairy free/vegan/gluten free friends: don’t tell our non-vegan, gluten- and dairy-loving friends but these blueberry oat pecan crumble bars just so happen to be gluten free and dairy free/vegan. but in a very secretive way, which is the best way, no?
blueberry crumb bars (with ginger! also gluten free)
- 204 g. (2 cups / 7 1/8 oz.) old-fashioned rolled oats, gluten free if necessary
- 90 g. (1/2 cup lightly packed / 3 1/8 oz.) dark brown sugar
- 2 teaspoons baking powder
- 1/4 teaspoon salt, optional
- 186 g. (6 ½ oz. / about 1 5/8 cups diced) pecans
- 50 g. (1/4 cup lightly packed / 1 ¾ oz.) dark brown sugar
- 2 teaspoons cornstarch
- juice of ½ lemon
- 320 g. (2 cups / 11 ¼ oz.) fresh blueberries, ideally those tiny wild ones, see notes
- preheat oven to 350° F. cut a piece of parchment paper to fit an 8” x 8” (20 cm x 20 cm) glass baking dish with overhang on 2 opposite sides to form a sling to make removing the bars easy (see photos).
- spread the pecans out on a rimmed baking sheet. toast the pecans for 8 – 10 minutes, stirring halfway through, until they are fragrant and just a shade darker. set aside to cool.
- put half of the oats in the bowl of a food processor fitted with the metal blade attachment (if you have a scale, you technically want to put 105 g. in the food processor). process for 2 – 3 minutes until the oats are broken down into a fine powder. we’re making oat flour so we want a fine grind, though since the bars will also have larger oat pieces, we don’t have to get too intense about grinding the oats totally into powder. transfer the oat flour to a large mixing bowl.
- put all but ¼ cup (16 g. / ½ oz.) of the pecans in the food processor. grind until a smooth pecan butter forms (about 2 minutes). you may need to stop the machine to scrape down the sides a few times. scoop 32 g. (heaping 1/8 cup / 1 1/8 oz.) of pecan butter out of the food processor bowl and set aside. chop or break into pieces the remaining ¼ cup of pecans that did not go in the food processor; keep separate.
- to the large mixing bowl with the oat flour, add the oats, brown sugar, baking powder, and (optional) salt. whisk the dry ingredients until thoroughly combined. add the dry ingredients to the food processor bowl that contains almost all of the pecan butter (set the empty mixing bowl aside for later). pulse until a dough forms. there shouldn’t be any dry pockets but the dough doesn’t need to be smooth.
- carefully scoop out 1 ½ cups of the mixture and use the back of the measuring cup to pack it into the bottom of the 8” x 8” baking pan to form the base crust. bake for 10 minutes, until the crust is fragrant and very lightly browned. take out of the oven and let cool for 10 minutes.
- add remaining pecan butter to the remaining mixture in the food processor and pulse until combined. transfer this crumble mixture to the empty mixing bowl and stir in the chopped pecans.
- in another medium mixing bowl, stir together the sugar, cornstarch, and lemon juice. gently fold in the blueberries.
- add the blueberry mixture to the pan with the crust and gently spread the blueberries into an even layer. sprinkle the crumble mixture over the top of the blueberry layer and press down gently (if you want large pieces of crumble, press them together between your fingers before sprinkling over the blueberry mixture).
- bake for about 30 minutes, until the crumble is lightly browned and the filling is bubbling on the sides. cool on a wire rack to room temperature, then refrigerate until cold. use the parchment sling to get the whole pan of bars out of the baking dish then a chef’s knife or pizza cutter to cut into bars. the bars cut, taste, and keep best refrigerated. store in an airtight container in the refrigerator for up to 5 days. the bars will seem to get moister over time, rather than drier (especially the bottom crust).
blueberry hierarchy, from most to least desirable (but still worth making):
fresh wild blueberries
good frozen wild blueberries (i like trader joe’s wild boreal blueberries or wyman’s brand)
fresh regular size blueberries in july or august
i wouldn’t bother making these bars with fresh blueberries out of season (july/august in the eastern US) or mediocre frozen blueberries. the blueberry flavor is the whole point and medicore berries just won’t provide it.
adapted from an adapted mishmash of heartbeet kitchen’s raspberry rhubarb crumble bars and smitten kitchen’s blueberry crumb bars.
please note this page contains affiliate links, which means that if you make a purchase after clicking from here, i will earn a small commission from amazon at no additional charge to you. i only link to products that i use and love. thank you for supporting tasty seasons!