Step 1: In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set aside.
Step 2: In a large mixing bowl, beat the softened butter and softened cream cheese with an electric mixer until light and fluffy, about 2-3 minutes.
Step 3: Add the granulated sugar and beat until well combined, scraping down the sides of the bowl as needed.
Step 4: Beat in the large egg and vanilla extract until fully incorporated.
Step 5: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Do not overmix.
Step 6: Gently fold in the finely diced fresh strawberries and white chocolate chips (if using).
Step 7: Cover the dough and chill in the refrigerator for at least 30 minutes, or up to 2 hours. This helps prevent spreading.
Step 8: Preheat your oven to 375°F (190°C). Line baking sheets with parchment paper.
Step 9: Scoop rounded tablespoons of dough onto the prepared baking sheets, leaving about 2 inches between each cookie.
Step 10: Bake for 10-12 minutes, or until the edges are lightly golden and the centers are set but still soft.
Step 11: Remove from oven and let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.