Preheat oven to 350°F. Line an 8x8 baking pan with parchment paper or grease it well.
In a large bowl, whisk melted butter and sugar until glossy. Add egg, lemon juice, lemon zest, and vanilla. Stir well.
Mix in flour, baking powder, and salt. Stir until just combined.
Gently fold in the chopped, dry strawberries.
Spread batter evenly in pan. Bake for 25–28 minutes until the top looks set and a toothpick comes out with a few moist crumbs.
Cool completely before glazing.
For the glaze, mix powdered sugar with lemon juice and mashed strawberries. Drizzle over cooled blondies, slice, and enjoy!