Somebody asked me at GDC, "So you bake, huh? What's the best thing you've ever baked?" No hesitation. No pause to consider. "Blueberry boy bait, first runner up in the 1954 Pillsbury Bake off (Juniors category). It's amazing." Here's the recipe from Smitten Kitchen. Go, make this today, make it right goddamn now. It's magical.
Even better, if you're looking to take your baking game to the next level, this is a great recipe to start with. It's no more complicated than a boxed cake recipe, and by experimenting with the sugars, you can take this from super soft to almost crunchy, with a sweet sugar layer on top and bottom. Adjusting the brown to white sugar ratio, or substituting coconut sugar, yield different, but still excellent, textures. Fresh and frozen blueberries both work great, and demonstrate the subtle, and sometimes not so subtle, differences in fruit selection. In fact, a little birdy told me that dried cherries soaked in brandy and drained work well in this. Of course, that's getting in to cranberry/craisin territory, which is a whole other thing.
Make this recipe. It's great, it's worth your time, and it goes over great at the office.