Place the frozen blueberries in a small microwave-safe bowl.
Heat the blueberries in the microwave for 60 to 90 seconds, or until fully thawed.
Set the thawed blueberries aside and allow them to cool completely.
In a small mixing bowl, sift together the all-purpose flour, baking powder, and salt.
Set the dry ingredients aside.
In a large mixing bowl, add the softened unsalted vegan butter.
Add the granulated sugar.
Cream the vegan butter and sugar together until the mixture is light, smooth, and evenly combined.
Add the lemon juice to the butter mixture.
Add the cooled thawed blueberries.
Mix until the blueberries are slightly mashed and fully incorporated into the butter mixture.
Gradually add the sifted dry ingredients to the wet mixture.
Mix until the dough is fully combined.
Add the white chocolate chips.
Fold the white chocolate chips into the dough until evenly distributed.
Cover the bowl with plastic wrap or a fitted lid.
Refrigerate the cookie dough for at least 30 minutes.
When ready to bake, preheat the oven to 400°F.
Line a baking sheet with parchment paper.
Scoop or roll the chilled dough into cookie portions.
Arrange the cookie dough portions evenly on the prepared baking sheet, leaving space between each cookie.
Place the baking sheet in the preheated oven.
Bake for 10 to 12 minutes, or until the cookie edges are just beginning to brown.
Remove the baking sheet from the oven.
Allow the cookies to rest on the baking sheet for several minutes before transferring them to a cooling rack.
Serve once cooled or slightly warm.