Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large bowl, cream together the softened butter and sugar until light and fluffy, about 2-3 minutes.

Mix in the vanilla extract until fully combined.

Gradually add the flour and salt to the butter mixture, mixing on low speed or by hand until just combined.

Add cold water, one tablespoon at a time, until the dough comes together into a smooth ball. Do not overmix.

Roll the dough out on a lightly floured surface to about 0.25-inch thickness.

Use a shell-shaped cookie cutter to cut out cookies. If you don’t have one, gently shape each piece by hand into a small oval and use a fork to create ridges resembling a seashell.

Place the shaped cookies onto the prepared baking sheet, leaving about 1 inch between each.

Bake for 18–22 minutes, or until the edges are lightly golden.

Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.