01 - Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper, leaving an overhang on opposite sides for easy removal.
02 - Whisk together flour, baking powder, and salt in a medium bowl. Set aside.
03 - In a large mixing bowl, combine melted butter and brown sugar. Stir until smooth and well incorporated.
04 - Beat in the egg and vanilla extract until the mixture is glossy and fully combined.
05 - Gently fold the dry ingredients into the wet mixture using a spatula. Mix just until no dry streaks remain—do not overmix.
06 - Fold in white chocolate chips, milk chocolate chips, and chopped Cadbury Mini Eggs until evenly distributed.
07 - Spread the batter evenly into the prepared pan. Press reserved whole Mini Eggs into the top surface, spacing them evenly.
08 - Bake for 22 to 25 minutes until the top is golden brown and a toothpick inserted in the center comes out with a few moist crumbs.
09 - Let cool completely in the pan. Using the parchment paper overhang, lift the blondies out and cut into 12 equal squares.