Soft and Chewy Loaded M&M Cookies

In a large mixing bowl combine the butter, sugar, brown sugar, egg, vanilla, and beat on medium until creamed. This should take 3-4 minutes.
If using a stand mixer use paddle attachment on medium-high speed.
Add the flour, pudding mix, baking soda, salt, and beat on low speed until just combined. (This should take about 1 minute)
Using a larger cookie scoop or your hands, form 12 equal-sized mounds of dough, roll into balls, and flatten slightly.
Place balls of uncooked dough on a large tray then cover with plastic wrap.
Chill dough in fridge for 3 hours. Do not skip this step. Unchilled dough will fall flat in the oven.
Preheat oven to 350 degrees and line cookie sheets with parchment paper.
Place dough in balls on baking sheet, spaced at least 2 inches apart. Bake for about 10 to 11 minutes.
Edges should be firm and tops should be just set.
Even if cookies appear slightly undercooked in the center remove them from the oven. The cookies firm up as they cool. Allow cookies to completely cool on cookie sheet.
Cookies will keep in a tightly sealed container at room temperature for up to one week or frozen up to six months.
Uncooked dough will keep in a tightly sealed container for five days or frozen for three months.