Preheat your oven to 350°F (175°C).
Cream together the softened butter and granulated sugar until light and fluffy.
Add in the egg and vanilla extract, mixing until well combined.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture, mixing just until incorporated.
Fold in the diced strawberries gently to distribute them evenly.
Scoop tablespoon-sized amounts of dough onto a lined 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 them cool on the baking sheet for 5 minutes before transferring to a wire rack.
Once cooled, dust with powdered sugar before serving if desired.