Line a square pan with parchment paper or saran wrap.
In a large bowl, mix the oats and flax.
Add the date paste, nut butter, and vanilla extract, and stir to combine. If your nut butter is too thick, heat it up in the microwave until it's a little more loose so that it's easier to mix in.
Carefully mix in the blueberries.
Press the mixture into the pan, top with the rest of the blueberries, and refrigerate overnight to set.
Cut into bars, then store in the refrigerator. They will be pretty soft, so if you want them a lot more sturdy, I would keep them in the freezer and set them out for a few minutes before you take them on the go!
