Chop the butter and place it in a microwave-safe mixing bowl. Microwave for 30 to 60 seconds until fully melted. Let it cool slightly so it does not cook the eggs.

Add the white caster sugar and light brown sugar to the melted butter. Stir well using a wooden spoon until smooth and glossy.

Mix in the whole egg, egg yolk, and vanilla extract. Stir until fully combined and thick.

Fold in the self-raising flour and salt. Mix gently until a soft dough forms. If the dough feels too sticky, add flour 1 tablespoon at a time.

Stir in the chopped chocolate chunks until evenly distributed.

Cover the bowl with clingfilm and refrigerate for at least 5 hours or overnight to improve flavor and texture.

Preheat the oven to 180°C fan or 200°C conventional. Line a flat baking tray with greaseproof paper. Remove the dough from the fridge and let it soften at room temperature for 30 minutes.

Scoop a heaped tablespoon of dough and roll into a ball. Repeat to make 12 to 14 cookie balls.

Place 3 to 5 dough balls on the tray, leaving space between each. Bake for 10 minutes until the edges are pale golden and the centers remain soft.

Remove from the oven and gently press one Mini Malteser Bunny and one Mini Egg into the top of each cookie.

Leave the cookies on the tray for 20 minutes to firm up as they cool and finish baking.