Step 1: Preheat your oven to 350°F (175°C) and line two large baking sheets with parchment paper or silicone mats.
Step 2: In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until the mixture is light and fluffy.
Step 3: Add the egg and vanilla extract to the butter mixture, beating well until fully combined.
Step 4: Stir in the dry instant strawberry pudding mix until the dough is a uniform pink color.
Step 5: In a separate medium bowl, whisk together the flour, baking soda, and salt.
Step 6: Gradually add the flour mixture to the wet ingredients, mixing just until no streaks of flour remain.
Step 7: Gently fold in the white chocolate chips using a spatula.
Step 8: Scoop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Step 9: Bake for 8-10 minutes, or until the edges are just set. Do not overbake; the centers should still look soft.
Step 10: Allow the cookies to cool on the baking sheet for at least 5 minutes before transferring them to a wire rack to cool completely.