01 - Preheat oven to 350°F. 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 fully combined.
03 - Incorporate eggs and vanilla extract into the butter and sugar mixture, blending until smooth.
04 - In a separate bowl, whisk together all-purpose flour, baking powder, and salt.
05 - Fold dry ingredients into the wet mixture until just combined, avoiding over-mixing.
06 - Transfer batter to the prepared pan, smoothing the top. Bake for 22 to 25 minutes, or until edges are set and a toothpick inserted in the center emerges with a few moist crumbs.
07 - Allow to cool completely in the pan before glazing.
08 - In a bowl, whisk powdered sugar with 2 to 3 tablespoons strawberry puree and lemon juice, if using, until smooth and pourable.
09 - Spread glaze over cooled brownies, let set for 15 minutes, then cut into squares and serve.