Preheat oven to 375-degrees. Grease a 9" x 13" casserole dish.
Add the flour, baking soda, and salt to a medium-sized bowl. Whisk the ingredients together and set the bowl to the side.
In a large bowl, add the softened butter and cream.
Next, add the granulated sugar, brown sugar, vanilla extract, and eggs to the bowl. Mix well.
Add the flour mixture to the bowl and mix all of the ingredients together.
Pour 1-1/2 cups of M&M's into the bowl and mix well.
Add the cookie dough to the casserole dish, spread out, top with the remaining M&M's, and bake for 20-25 minutes or until the cake tester comes out clean.
Let the cookies cool for at least 30 minutes before cutting.