Preheat your oven to 190 degrees and line two baking trays with baking paper.
Place the butter, sugar and vanilla in the bowl of an electric mixer and combine until pale and creamy.
Beat through the eggs one at a time and combine well between each addition.
Remove the bowl for the mixer stand and carefully stir through the flour and baking powder.
Roll tablespoons of mixtures into balls, place on the baking trays making sure you leave enough space in between each cookie as they will spread a little. Flatten the top of the cookie slightly and decorate with the red and green M&M's. Continue to create cookies until all the mixture has been used.
Place baking trays in the oven and bake for 10 – 12 minute or until the cookies begin to brown on top. Allow the cookies to cool on the baking trays for 5 minutes before carefully transferring to a wire rack to cool completely.