Preheat the oven to 180C
In the stand mixer bowl, add in chunks of butter, light brown sugar, white sugar, baking soda, salt and vanilla extract
Using the paddle attachment, pulse for a few times to combine the ingredients in the mixer bowl. On medium speed, mix for 3 minutes until pale and fluffy. Stop to scrap the sides of the bowl if necessary
Add egg and mix on low speed until well combine. About 1 minute.
Add in the flour all at once. Pulse for a few times to prevent flour from flying out of the bowl. Turn to low speed and mix for about 10 to 15 seconds. Mixture will look dry, crumbly and not fully combine. That's perfectly ok.
Now add in all the chocolate chips, cranberries and oats. Pulse for a few times. Remove bowl from mixer and fully combine by hand using a spatula. Stop mixing once all the flour has been incorporated.
Scoop out rounds of dough using an ice cream scoop. You can also scoop out with a large spoon and shape round with your hands. Compress the round doughs into shape of disks.
Place cookie dough disks on a baking tray lined with baking paper, spacing them about 2 inches apart to allow room for spreading.
Bake for 15 to 20 mins, depending on the size of the dough. The cookies should look light golden brown on the surface.
Allow to cool on the baking tray for at least 10 minutes before removing them for storing