In the bowl of an electric stand mixer using the paddle attachment or a large bowl with a handheld mixer cream butter, white sugar and brown sugar for 2 minutes or until smooth and creamy.
With the mixer on low, add in the peanut butter and mix to combine.
Add in eggs one at a time allowing each to fully incorporate before adding the next. Add the vanilla next.
Scrape down the sides of the mixer to ensure all batter is being mixed.
With the mixer on low speed, add in the flour and baking soda. Stir only to combine, do not over mix.
Gently mix in oats, smarties and chocolate chips.
Roll dough into 2 tablespoon balls and place on a baking sheet lined with parchment paper.
Flatten dough using the bottom of a water cup. Dough should be about 1.5 inches tall.
Bake at 350 degrees F for 8-10 minutes. Over baking the cookies will make them hard.
Cool on the tray for about 8 minutes before transferring to cooling racks.