Ask an adult to preheat your oven to 190°C and to help you line a baking tray with baking paper.
Mix together the flour and baking soda in a medium sized bowl.
In a seperate bowl, use electric beaters (with an adults help) to beat the butter, brown sugar, and vanilla until they are all mixed well together which should take about 2 minutes.
Then add in the flour and baking soda mixture and beat it until a dough comes together.
With a wooden spoon, stir in the mini M&Ms. Using a teaspoon, scoop and roll the cookie dough into balls and place them on the lined baking tray - make sure to leave room around each one because they will spread out! Using the back of a fork, gentle press down on the cookie dough balls, so slightly flatten them.
Bake in preheated oven for 10 to 12 minutes or until edges are lightly golden. Allow to cool on a wire rack before eating!