Christmas Monster Cookies

0 Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.
1 In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
2 Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
3 In a separate bowl, whisk together the old-fashioned oats, all-purpose flour, all purpose flour, baking powder, baking soda, and salt.
4 Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
5 Fold in the creamy peanut butter until evenly distributed throughout the cookie dough.
6 Gently fold in the M&M's or Smarties, chocolate chips, and chopped nuts if using.
7 Drop rounded tablespoons of dough onto the prepared baking sheets, leaving enough space between each for spreading.
8 Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden but the centers are still soft.
9 Allow the cookies to cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.