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 incorporated.
03 - Incorporate eggs and vanilla extract into the wet mixture and whisk until smooth.
04 - In a separate bowl, blend all-purpose flour, baking powder, and salt until evenly distributed.
05 - Fold the dry ingredients into the wet ingredients until just combined, taking care not to overmix.
06 - Spread the batter evenly into the prepared baking pan, smoothing the surface with a spatula.
07 - Place pan in oven and bake for 22 to 25 minutes, or until edges are set and a toothpick inserted in the center yields a few moist crumbs.
08 - Remove pan from oven and allow brownies to cool completely in the pan.
09 - In a bowl, whisk powdered sugar, strawberry puree, and lemon juice, if using, until the glaze is smooth and pourable.
10 - Evenly spread the glaze over the cooled brownies. Let set for 15 minutes, then slice into squares for serving.