Preheat your oven to 350°F (175°C) and grease a 9x9 inch baking pan or line it with parchment paper for easy removal.
In a large bowl, whisk together the melted butter, brown sugar, and granulated sugar until well combined and smooth.
Add the eggs, one at a time, mixing well after each addition, then stir in the vanilla extract.
In a separate bowl, combine the all-purpose flour, baking powder, salt, lemon zest, and lemon juice. Gradually add this dry mixture to the butter and sugar mixture, stirring until just combined.
Gently fold in the diced strawberries, taking care not to overmix.
Pour the batter into the prepared baking pan, spreading it evenly.
Bake for 25-30 minutes, or until the edges are golden and a toothpick inserted into the center comes out clean.
Allow the blondies to cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.
Once cool, slice into squares and sprinkle with powdered sugar if desired.
Notes
Optional to dust with powdered sugar before serving.