Put all the ingredients in your blender container. I like to use frozen IQF berries, the kind that are loose in a big freezer bag, for simple convenience. You may want to adjust the amount of milk. More milk will produce a thinner smoothie, and less will make a thicker one.
Blend it all together. Check for taste and consistency: too thick? Add milk. Do you want more chocolate flavor: add a bit more cocoa powder. Not sweet enough? Dollop in a spoonful of jam.
After your adjustments, blend again, then pour the smoothie into a large glass, stick in a straw, and indulge.