01 - Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - In a medium bowl, whisk together the flour, baking powder, and salt until well blended. Set aside.
03 - In a large mixing bowl, combine the melted butter and brown sugar. Stir until smooth and fully incorporated.
04 - Beat in the egg and vanilla extract until the mixture is glossy and smooth.
05 - Gently fold the dry ingredients into the wet mixture using a spatula. Mix just until combined—do not overmix.
06 - Fold in the 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 onto the surface, lightly embedding them into the batter.
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 overhang, lift the blondies out and cut into 12 equal squares.