Combine dried blueberries and apple juice or water in a microwave-safe cup or bowl. Cover tightly with plastic wrap and microwave on high or 45 seconds. Set aside to cool. Blueberries will absorb the juice (or water) and plump up a bit.
Preheat oven to 325˚F (150˚C). Line two sheet pans with parchment paper.
Combine flour, baking powder and salt. Stir well, then add cooled blueberries and lemon zest. Stir again, then set aside.
In the bowl of an electric mixer, cream the butter and sugar together, until light and fluffy.
Slowly add the dry ingredients, mix until completely combined.
With a cookie scoop or tablespoon, scoop dough onto prepared sheet pans, 1 ½ inches apart. I use a 1 ½ tablespoon cookie scoop (size and number of cookies will depend on the size of your scoop). Sprinkle each cookie lightly with sugar and bake for 15 to 20 minutes, until light golden brown. Remove to a wire rack to cool.
