Preheat oven to 180 degrees C. Line 2 baking trays with baking paper.
Using a silicone spatula or a wooden spoon cream together your sugars and butter. After the mixture is smooth and creamy add the vanilla extract. Add the egg in and mix until the egg is combined properly.
Add the flour in 3 batches. After you have added the flour the mixture should look a bit dry, that's okay. Then add your chocolate chips and m&ms to the mixture and it should all come together.
Use 2 tablespoons of cookie dough and roll them together. Put it on the baking paper and slightly flatten. Do this for your remaining dough. Make sure there is a bit of space in between each cookie because they will spread out a lot.
Put the cookies in the oven for 15-18 minutes depending on how soft of crunchy you like them. When you take the cookies out they will still be soft but don't put them in any longer than 18 minutes because they will harden a lot when they cool.
To make baking paper stick to the baking tray, splash the baking tray with a little bit of water and then put the baking paper on.