Since the thick filling needed to cool down and hang out in the refrigerator for awhile, I made sure to get that out of the way early this morning. Thankfully, in my morning haze, all I had to do was toss the blueberries with sugar and freshly squeezed orange juice in one of our saucepans. Once I had brought it up to a boil, then eased the heat back to let the trio simmer, the blueberries bounced around to become tender and start to burst, releasing their tart juices. Which happened to be just enough time to get the dogs up, fed and outside!
It was plenty loose at this point, which wouldn't make for a good bar cookie filling, so adding a bit of cornstarch (mixed with water first to ensure no lumps) was supposed to do the trick to tighten up the excess liquids (more on this in a bit). Just be sure that the blueberry mixture sits at a full boil for a minute or so to make sure the starch activates. Transferred to a bowl, the quick jam-like filling is then covered with plastic wrap (taking care to make sure the wrap is directly on the surface to prevent a skin) and left in the refrigerator to chill down.
When I finally was ready to get the bars going, all I needed to do was quickly get the oat crumble together and it was ready for the oven! Hearty old-fashioned oats, flour, rich brown sugar, a bit of orange zest (since we used the juice in the filling!) hold down the fort as the dry ingredients and to bring them together, a mess of cubed butter was added to be cut in with a pastry blender. If you wanted to haul out a food processor to do this, by all means go ahead, but I didn't want to dirty that up today. You are not trying to form a dough per se, you're more looking for the mixture to resemble coarse crumbs instead of a smooth dough.
Half of it was patted into a baking pan, followed by that cooled blueberry filling to be spread over the top. The remaining half of those oat crumbles was scattered on top, using a light hand to press them in slightly. You want to bake these long enough to bind the oats together, letting them turn golden and slightly crispy. Not the easiest request, and I know it was quite hard to do myself, but you don't want to slice these into bars while warm as the filling would not have had time to set up. So, try and let them cool completely first.
After what felt like an eternity, I cut out a couple squares for us to test (a requirement, you know!) and was first very pleased with how vivid and striking the filling ended up. However, apparently the recipe was short on the cornstarch (or our berries were extra juicy!) as my filling was a little more oozy that I expected - even with a stint in the refrigerator, the filling didn't seem to hold together as much as I would have liked.
That buttery oat top and bottom crust surrounding the filling, with its brilliance of blueberries spiked with orange, a smile hastily displayed on my face as I reveled in my portion of this sweet, decadent treat. And, even though there was plenty of butter involved (I'm sure I made Miss Deen proud), I just told myself there were plenty of antioxidant-rich blueberries and vitamin-filled orange juice that we could label this a healthy snack! I realize that's a stretch, but it works for me. They ended up being pretty messy to cut and eat (and no doubt trouble to bring into the office tomorrow!), however, I bet no one will mind as they will be too busy licking their fingers clean to care!
Blueberry Oatmeal Squares