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 homogenous.
03 - Add eggs and vanilla extract to the wet mixture and blend until smooth and fully combined.
04 - In a separate bowl, whisk together flour, baking powder, and salt.
05 - Gently fold the dry ingredients into the wet mixture just until combined. Take care not to over-mix.
06 - Pour the batter into the prepared pan and smooth the surface using a spatula.
07 - Bake for 22 to 25 minutes, or until the edges are set and a toothpick inserted into the center emerges with a few moist crumbs attached.
08 - Allow brownies to cool completely in the pan before glazing.
09 - In a small bowl, whisk powdered sugar, strawberry puree, and lemon juice (if using) until smooth and pourable.
10 - Spread glaze evenly over cooled brownies. Let set for 15 minutes, then slice into squares and serve.