Cream together the butter and sugars until fluffy. Add the eggs and vanilla. Blend well.
Sift together the 2½ cups flour with the baking soda and salt. Add the sifted flour to the butter mixture. Blend well. For a little denser cookie add the other ¼ cup flour.
Fold in the M&M's.
Roll dough into 2 inch balls and place on a parchment lined cookie sheet.
Bake for 9 minutes.
Cool on a wire rack.
ENJOY!
Recipe by Sugar n' Spice Gals at https://sugar-n-spicegals.com/mm-peanut-butter-cookies/