Preheat oven to 350 degrees. Line baking sheet with parchment paper and set aside.
In a medium bowl, whisk together flour, baking soda and salt and set aside.
Using a stand or electric mixer or stand mixer, beat the butter and sugar until light and creamy for at least 3 minutes. Add the pudding mix, vanilla and eggs and beat until well combined.
Slowly add the dry ingredients to the wet ingredients and mix until just combined. Add the M&Ms and stir with a rubber spatula.
Drop cookies by the 1/4 cup onto the prepared baking sheet. Bake for 10-12 minutes, or until slightly golden and just set on the top. Allow to cool on the baking sheet for two minutes then transfer to a baking rack to cool completely.