Can you use Frozen Blueberries ?

I freeze about 50lbs each summer just so I can pull a handful out whenever I want. As Merrill says, in this case thaw first. If you were making a smoothie, just toss them in the blender still frozen. I find putting frozen blueberries in pancake batter means they do not "bleed" into the pancake you end up with great 'cakes. Likewise for a sauce, just toss in a handful and they thaw in a few seconds releasing great flavor.

Yes, you can -- just thaw them before you crush them.