Pre-heat oven to 350 degrees.
In a large mixing bowl, combine, butter, sugar, brown sugar, vanilla, egg, flour, baking soda, chocolate chips & salt.
Roll into Tablespoon sized balls and place on a nonstick pan.
Bake for 10 minutes or until cookies are set.
Remove from oven. Quickly place valentine M&M’s onto the warm cookies.
Transfer to a cooling rack.