Preheat your oven to 350°F (175°C).
In a mixing bowl, cream the softened butter and granulated sugar together.
Add the egg, lemon zest, and lemon juice to the mixture, and mix until combined.
In another bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Gently fold in the blueberries to avoid breaking them.
Drop spoonfuls of dough onto a baking sheet lined with parchment paper.
Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden.
Remove from the oven and let cool on the baking sheet for a few minutes before transferring to a wire rack.
Dust with powdered sugar before serving, if desired.