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 thoroughly blended.
03 - Add eggs and vanilla extract to the wet mixture, blending until the batter is smooth.
04 - In a separate bowl, whisk together all-purpose flour, baking powder, and salt.
05 - Gently fold the dry ingredients into the wet mixture just until combined. Avoid over-mixing for optimal texture.
06 - Transfer the batter to the prepared baking 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 a few moist crumbs.
08 - Allow the brownies to cool completely in the pan before glazing.
09 - In a small bowl, whisk powdered sugar with strawberry puree and lemon juice (if using) until smooth and pourable.
10 - Spread glaze over cooled brownies. Allow to set for 15 minutes, then cut into squares and serve.