Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper and set aside.
In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
Beat in the egg, vanilla extract, lemon zest, and lemon juice until well combined.
In a separate bowl, whisk together the flour, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the white chocolate chips or chunks until evenly distributed throughout the cookie dough.
Using a cookie scoop or spoon, drop rounded tablespoons of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden.
Remove the cookies from the oven and let them cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.