Preheat the oven to 180°C (350°F) and line a 9" baking pan with baking paper.
Beat the melted butter, sugar and brown sugar together until light and fluffy.
Add in the eggs and the vanilla extract and beat.
Add in the cornflour, baking powder and flour and mix until all combined.
Mix in the M&M Easter eggs and mini chocolate eggs.
Spread half of the mixture in the base of the baking pan.
Lay out the Malteser Bunnies and top with the remaining mixture.
Place in the oven and bake for 25-35 minutes. Check the bars at 25 minutes the outside and top should be set but the middle slightly wobbly. If it is too 'underdone' for you, baking for a further 10 minutes.