Preheat the oven to 180°C or 350°F and line a baking sheet with parchment pepper.
In a mixing bowl, whisk together flour, baking soda and salt.
1 ½ cups All-Purpose Flour, 1 teaspoon Baking Soda, ¼ teaspoon Kosher Salt
In another bowl, cream butter and both granulated sugars and brown sugar, then add the egg and vanilla. Mix until combined.
½ cup Granulated Sugar, ⅓ cup Brown Sugar, 125 g Unsalted Butter, 1 Egg, 1 teaspoon Vanilla bean paste
Add the flour mixture and mix until incorporated DON’T overmix the dough.
Mix in the Smarties using a spatula. Scoop 1 tablespoon of the batter for one cookie (about 14 equal cookies). Tip: I prefer to add the Smarties whole, but you can crush them if you like.
1 cup Smarties
Roll them into balls and place them on the baking tray. Tip: I leave enough space between the cookie dough balls because these cookies tend to spread slightly while baking.
Bake for 10–15 minutes. Allow the cookies to cool on the tray for about 10 minutes, then transfer them to a wire rack to cool completely. Serve and enjoy!
Notes
I highly recommend sifting the dry ingredients to avoid lumps in your batter.