Preheat your oven to 350°F and line two baking sheets with parchment paper.
In a large bowl, whisk together the flour, baking powder, and salt.
In another bowl, cream together the softened butter and granulated sugar until fluffy. Then beat in the egg and vanilla until pale and fluffy.
Gradually add the dry ingredients to the wet ingredients, mixing until the dough comes together. Fold in the cooled blueberry jam.
Use a large cookie scoop to portion out the dough onto the prepared baking sheets. Sprinkle with sugar if desired.
Bake for 10 minutes, then let them cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.
Get ready to delight in the irresistible combination of soft, chewy cookies and juicy blueberries – it's a match made in dessert heaven!