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 the m&m's and fold into the batter. Reserve some for topping.

Use a icecream scoop to scoop out the batter and place it in the tray, top with m&m's.

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

Remove it and let it cool down for 10 mins in the pan.

Now remove this and cool it in a cooling rack.

Serve immediately or store in a air tight cookie jar.