In a medium bowl, combine the blueberries, granulated sugar, and lemon juice. Gently toss to coat and let sit for about 15 minutes to release the juices.

Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper.

In a large bowl, whisk together the flour, baking powder, and salt. Add the cold, cubed butter and use a pastry cutter or your fingers to mix until the mixture resembles coarse crumbs.

Pour in the milk and vanilla extract, stirring until just combined. Do not overmix.

Turn the dough out onto a floured surface and gently knead it a few times until it comes together. Pat it into a 1-inch thick rectangle.

Cut out shortcakes using a round cutter or a glass and place them on the prepared baking sheet.

Bake for 12-15 minutes, or until golden brown. Remove from the oven and let cool slightly.

While the shortcakes are baking, whip the heavy cream with powdered sugar and vanilla extract until soft peaks form.

To assemble, slice the shortcakes in half, spoon some of the blueberry mixture onto the bottom half, add a dollop of whipped cream, and then place the top half back on. Serve immediately.