01 - Preheat the oven to 350°F. Grease and line an 8x8-inch baking pan with parchment paper.
02 - In a large bowl, whisk together the melted butter, granulated sugar, and strawberry puree until evenly blended.
03 - Add eggs and vanilla extract to the bowl. Whisk until the mixture is completely smooth.
04 - In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.
05 - Fold the dry ingredients into the wet mixture just until combined. Avoid over-mixing to maintain a tender texture.
06 - Pour the prepared batter into the lined baking pan. Smooth the surface with a spatula.
07 - Bake for 22 to 25 minutes, or until the edges are set and a toothpick inserted in the center emerges with a few moist crumbs.
08 - Allow brownies to cool entirely in the pan before glazing.
09 - In a bowl, whisk together powdered sugar, strawberry puree, and lemon juice (if using) until smooth and pourable.
10 - Spread the glaze evenly over the cooled brownies. Let set for 15 minutes, then cut into squares and serve.