01 - Preheat oven to 350°F (175°C). Grease and line an 8x8-inch baking pan with parchment paper.
02 - In a mixing bowl, whisk together melted butter, granulated sugar, and strawberry puree until well combined.
03 - Add eggs and vanilla extract to the wet mixture and mix until smooth.
04 - In a separate bowl, whisk together flour, baking powder, and salt.
05 - Fold dry ingredients into wet mixture just until incorporated, avoiding over-mixing.
06 - Pour batter into prepared pan and smooth the surface with a spatula.
07 - Bake for 22 to 25 minutes, or until edges are set and a toothpick inserted in the center yields just a few moist crumbs.
08 - Allow brownies to cool completely in the baking pan.
09 - In a small bowl, whisk powdered sugar, strawberry puree, and optional lemon juice until smooth and pourable.
10 - Spread glaze uniformly over cooled brownies. Let set for 15 minutes, then cut into squares and serve.