Preheat your oven to 190C/170C Fan and line a 9x9inch Square Tin with parchment paper, and leave to the side for now.
Whisk/Mix the Plain Flour, Bicarbonate, Salt and Cornflour together so its evenly distributed – leave to the side.
In a larger bowl, melt the butter. Add in the two sugars, and whisk for about 2 minutes so the sugar starts to dissolve and the mixture is smooth. Add in the Egg and the Vanilla, and whisk again briefly till smooth. (I used an electric whisk)
Add in the Dry Ingredients, the Mini Eggs (apart from a handful), and the Chocolate Chips and mix with a spatula till a thick cookie dough is formed.
Press the mixture into the bottom of the tin and press in the handful of Mini Eggs into the top for decoration. Bake the traybake in the oven for 18-22 minutes, until the top of the cookie bake looks ‘dry’!
Leave the cookie bake to cool for about 10 minutes, then leave to cool fully on a wire rack. Cut the bake into 4×4 for decent sizes, or 5×5 for smaller ones! Enjoy!
If you don’t want to use Mini Eggs you can use M&Ms, Smarties, or anything chocolatey. I wouldn’t advise using Creme Eggs though because it will just turn into a sloppy mess! You could use caramel eggs, but they might need 5 minutes longer in the oven if they ooze everywhere.
These delicious beings will last in an airtight container for up to 5 days, but honestly, they’ll be eaten before then.
Try Microwaving them when they’ve cooled if you want a gooey cookie, or even add a scoop of ice cream!
If you can't access Cornflour - use 25g more flour, but the texture will change.
Also, if you can't access Plain Flour, you can use self raising, but again the texture will change.
If you can't find bicarbonate of soda, leave it out - but again the texture might change!