M&M Pudding Cookies

In a large bowl or stand mixer fitted with a paddle attachment, cream together the butter and sugars until smooth.
Add the dry pudding mix, eggs, additional egg yolk, and vanilla. Beat for about one minute on medium speed.
In a separate bowl, whisk together the flour, baking soda, and salt.
Add dry ingredients to the wet ingredients a little at a time and mix until combined.
Gently fold in the M&Ms, until evenly distributed throughout the dough.
Cover the mixing bowl with plastic wrap and chill for at least two hours and up to 2 days.
Remove from refrigerator a little while before baking so the dough can soften a bit and is easier to work with.
Preheat the oven to 350°F and line a large baking sheet with parchment paper.f
Use a medium cookie scoop to portion dough at least two inches apart.
Bake the cookies for 11 to 13 minutes until the edges are golden brown. Press additional M&Ms into the cookies as soon as they come out of the oven if desired.
Allow the cookies to cool on the pan for a couple of minutes before transferring to a wire rack.