Preheat the oven to 350°F. Line a baking sheet with parchment paper.
In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add the vanilla extract and egg to the butter mixture, mixing until well combined.
Incorporate the softened cream cheese into the mixture, blending until smooth.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the white chocolate chips and chopped Reese's Peanut Butter Cups.
Drop tablespoon-sized balls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are lightly golden. Remove from the oven and let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.