01 - Preheat oven to 350°F. Generously grease and line an 8x8-inch baking pan with parchment paper.
02 - In a large mixing bowl, whisk together melted butter, granulated sugar, and strawberry puree until well combined.
03 - Add eggs and vanilla extract to the bowl; mix until the batter is smooth and fully blended.
04 - In a separate bowl, whisk together all-purpose flour, baking powder, and salt.
05 - Gently fold the dry mixture into the wet ingredients, stirring just until no dry pockets remain. Avoid over-mixing.
06 - Transfer batter to the prepared pan, smoothing the surface with a spatula for even baking.
07 - Bake for 22 to 25 minutes, or until edges are set and a toothpick inserted into the center retrieves a few moist crumbs.
08 - Allow brownies to cool fully in the pan to maintain structure and moisture.
09 - In a small bowl, whisk powdered sugar, strawberry puree, and lemon juice (if using) until smooth and pourable.
10 - Spread glaze evenly over cooled brownies. Let stand for 15 minutes to set, then cut into squares and serve.