Homemade Cookies M&M

Ingredients:
260g AP Flour
2 tbsp cornflour (I opt out)
1-1/4 tsp baking soda (accidentally I used baking powder instead of soda)
170g butter
130g castor sugar
140g brown sugar
1 egg (whole)
1 egg yolk
1 tsp vanilla essence
200g Mini M&M

Method:

1. Preheat the oven to 180 deg C.  Line baking sheets with parchment paper, greased or silicone baking mats.
2. In the bowl of an electric mixer, combine the butter & both sugar.  Beat together on medium-high speed until light & fluffy (2-3 mins)
3. Blend in the eggs one at a time, scraping down the bowl as needed.  Mix in the dry sifted ingredients on low speed just until well incorporated.  Then use a spatula to fold in the chocolate chips.
4. Divide the dough using a teaspoon for measuring.   Roll each portion of dough into a ball.   Place on the prepared baking sheets/mats, a few inches apart.
5. Bake 10-12 mins.   Let cool on the baking sheets/mats (5-10 mins) then transfer to a wire rack to cool completely.   Keep in an air-tight container.