Line a 13X9 inch baking dish with parchment paper.

In a bowl, either by hand or with an electric mixer, cream together cold diced butter and sugar until well combined. Mixture will appear crumbly, this is okay. Add in vanilla extract, mix. Slowly add in flour, cup by cup. Mixture will be separated and crumbly. Keep mixing, it will take some time but soon a dough will start to form. Mine too about 10 minutes of mixing.

Add in green sparkling sugar, mix.

Press dough into your prepared baking dish with parchment paper and flatten out. I did this with my hands and then used a flat cup to help smooth it out. Sprinkle more sprinkles on top and press into the dough. Chill in the fridge for 30 minutes.

Meanwhile, preheat oven to 350F and take out a baking tray. Don't grease, helps the cookies not spread as much. Take dough out of fridge and cut into 1/2 inch squares using a sharp knife. Place on baking tray about 1 inch apart. Repeat. Bake for 8-10 minutes and keep remaining dough in the fridge between baking.

Once cooked let sit for 5 minutes before transferring to a plate or rack.

Repeat with remaining dough.

ENJOY :)