Combine dried blueberries and apple juice or water in a microwave-safe cup or bowl. Stir to coat. Cover the bowl or cup with a damp paper towel and microwave on high or 45 seconds. Stir again and set aside to cool while you make the dough.

Preheat oven to 350˚F (177˚C). Spray two 12-cup mini muffin pans (or 1 24-cup mini muffin pan) with non-stick cooking spray. Set aside.

Combine butter, sugars, lemon zest, vanilla and salt in a medium-size bowl and stir with a silicone spatula or wooden spoon well until smooth and creamy.

Add the flour and cornstach and stir from the bottom up until completely incorporated. The dough will be a little crumbly but make sure there is no dry flour at the bottom of the bowl.

Drain off any excess liquid from the plumped blueberries then turn them out onto several thicknesses of paper toweling. Pat well to remove any extra moisture.

Add the blueberries to the dough and stir gently to evenly incorporate.

Using a small cookie scoop or tablespoon scoop up the dough into 24 portions. Each one should be approximately 1 tablespoon or right around 30g. Place the scoops of dough in the cups of the prepared pan and flatten with your hand. The dough will pretty much fill the cups. Sprinkle lightly with sugar and bake until the tops are gold brown, about 12-15 minutes.

At this point, you can leave the shortbread bites just as they are or flatten the tops with the bottom of a small glass or metal measuring cup and sprinkle with a bit more sugar. Allow the cookies to cool in the pan for 5 minutes, then use a thin-bladed, small sharp knife along one edge to gently remove the cookies to a cooling rack.

Allow to cool completely than store in an airtight container. These cookies also freeze well!