In a stand mixer, mix sugar, shortening, eggs, and vanilla together thoroughly, until mixture is light and fluffy.
In a medium bowl, whisk together flour, baking soda, and salt. On low speed, slowly add dry ingredients to wet ingredient mixture in stand mixer.
After scooping dough balls onto baking sheet, use the remaining ¾ cup m&ms to press 3-4 m&ms on top of each dough ball. The cookies look great with a few extra m&ms sitting on top.
Slightly adapted from Robbi's m&m cookie recipe on AllRecipes.com