Melt the butter in a microwave-safe bowl, heating in short bursts until fully melted. Mix in white caster sugar and light brown sugar until well combined.

Add the egg, yolk, and vanilla extract, stirring until smoothly incorporated.

Gradually fold in self-raising flour and salt until a crumbly dough forms. Add chocolate chunks, folding until evenly distributed.

Cover with cling film and chill in the refrigerator for at least 5 hours, ideally overnight.

Preheat oven to 180°C for fan-assisted or 200°C for conventional. Line a baking tray with greaseproof paper.

Scoop and roll dough into balls, about 30g each. Space cookie balls evenly on the baking tray.

Bake for approximately 10 minutes until edges are pale golden and centers remain soft.

Immediately press a Mini Malteser Bunny and Mini Eggs into each cookie.

Cool on the tray for about 20 minutes before transferring to a wire rack to finish cooling.