Preheat oven to 180 degree C.Line a baking tray with parchment paper.

Mix butter,brown sugar,white sugar,egg,vanilla in a bowl. Mix well till creamy.

Add in baking soda and salt and mix well.Add in flour and mix well.

Now add 1 cup of m&m's and fold into the batter. Reserve some for topping.

Use icecream scoop to scoop out the batter and place it in the tray, top with m&ms

Pop it in the oven and bake for 8 to 10 mins till the cookies are almost done.