01 - Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper, allowing overhang for easy removal.
02 - In a medium bowl, whisk together flour, baking powder, and salt until well blended. Set aside.
03 - In a large bowl, combine melted butter, brown sugar, and granulated sugar. Whisk until smooth and fully incorporated.
04 - Add eggs and vanilla extract to the butter mixture. Whisk thoroughly until the mixture is glossy and well 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 - Stir in the chopped Mini Cadbury Easter Eggs and white chocolate chips, reserving a few pieces for topping.
07 - Spread the batter evenly into the prepared pan. Sprinkle the reserved Mini Eggs and white chocolate chips over the surface.
08 - Bake for 23–26 minutes until golden brown. A toothpick inserted in the center should emerge with a few moist crumbs, not wet batter.
09 - Cool completely in the pan before lifting out using the parchment overhang. Cut into 16 squares and serve.