Preheat the oven to 350°F (175°C). Grease and line an 8x8 inch baking dish with parchment paper, allowing some overhang for easy lifting later.
In a large mixing 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. Stir in the vanilla extract until fully incorporated.
In a separate bowl, whisk together the flour, baking powder, salt, lemon zest, and lemon juice. Gradually add the dry ingredients to the wet ingredients, stirring until just combined.
Gently fold in the chopped strawberries, ensuring even distribution throughout the batter.
Pour the batter into the prepared baking dish, spreading it out evenly with a spatula.
Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out clean with a few moist crumbs.
Remove from the oven and allow to cool in the pan for about 10 minutes. Then lift the blondies out of the pan using the parchment overhang and let them cool completely on a wire rack.
Once cooled, dust with powdered sugar if desired, and cut into squares for serving.