Add the flour to a large bowl. Rub the butter into it to create a breadcrumb-like mixture then stir in the sugar.
In a small bowl or mug, whisk the egg, vanilla extract, lemon extract and green food colouring together until smooth.
Pour the green mixture into the bowl with your dry ingredients and mix well. When it's starting to come together, use your hands to press it into a ball of dough.
Refrigerate the dough for 30 minutes. In the meantime, preheat your oven to 180°C/350°F and line a large tray with baking paper.
Divide the dough into 12 pieces. Roll each piece into a ball then gently flatten them to make ½-inch thick discs.
Place the cookies on your tray, leaving some space for spreading, and bake for 11-12 minutes. You'll know they're done when they no longer look 'wet' in the middle.
Gently press the sprinkles into the cookies while they're still warm- this will help them stick.
Let them cool on the tray before enjoying.