Preheat oven to 180C degrees. Grease a frying pan or cake tin. Set aside.
Sift flour, baking soda, baking powder and salt together in a bowl.
Use an electric stand mixer or a hand mixer and beat together the butter and sugars on medium speed for about 3 minutes until creamy and fluffy. Add the eggs and vanilla extract and beat until combined. Add the dry ingredients and mix until combined. Be mindful not to overmix. Fold in chocolate chunks or chopped chocolate Easter eggs.
Spoon and press the cookie dough into the prepared pan or tin. Bake for 20-25 minutes until golden but still a little soft in the centre. If it is browning too quickly at the edges, place some foil loosely on the cookie cake for the rest of the cooking time. Remove from oven and place on a wire rack. Allow to cool.
As with any good cookie, the leftovers will freeze just fine. If your family is like mine, though, there will be no leftovers.