Preheat the oven to 350°F (175°C).

In a mixing bowl, whisk together the flour, baking soda, baking powder, and salt.

In another bowl, cream together the softened butter, brown sugar, and granulated sugar until smooth.

Beat in the egg, prune juice, and vanilla extract until well combined.

Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Fold in the nuts and/or chocolate chips if using.

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.

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