Beautiful! I took these to a Valentine's cookie exchange party and they complemented the other contributions which were mostly regular chocolate. I didn't need to bake them the full 15 minutes. This dough is hard and a little frustrating to work with in the food processor and also getting the M&Ms to stick in it, but the final result is worth it.
I have made this recipe for almost 20 years. I found it in a Betty Crocker Contest Winner Cookbook. It is always a hit. I dip one edge of the cookie in the 1/2 cup of melted vanilla chips and drizzle it with 1/3 cup of melted semi-sweet chocolate chips.