01 - Preheat your oven to 350°F (175°C). Line an 8-inch square baking pan with parchment paper, ensuring an overhang for easy removal.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set this mixture aside.
03 - In a large bowl, whisk the melted and cooled unsalted butter with the light brown sugar until the mixture is smooth. Incorporate the large egg and pure vanilla extract, whisking until thoroughly combined.
04 - Gradually fold the dry ingredient mixture into the wet ingredients using a spatula. Mix until just combined; avoid overmixing.
05 - Gently fold in the chopped maraschino cherries and white chocolate chips into the batter.
06 - Spread the batter evenly into the prepared baking pan. Bake for 23–26 minutes, or until the edges are golden brown and a toothpick inserted into the center emerges with a few moist crumbs.
07 - Allow the blondies to cool completely in the pan on a wire rack. Once cooled, lift them out using the parchment overhang. Cut into 16 squares.