In a large mixing bowl, combine the flour, baking soda, baking powder, and salt, and whisk till evenly mixed.
Transfer mixture to the mason jar. Add each of the remaining ingredients to the mason jar as an individual layer.
The order is up to you, but for maximum visual appeal, we suggest this sequence: oats, M&Ms, brown sugar, granulated sugar, and topped off with chocolate chips.
You may need to tamp down with a pestle in between layers to get all ingredients to fit.
For a printable label with baking instructions, click on the graphic above. Print it out, tie it to your jar with some festive ribbon, and voila, you’ve got a homemade gift to give.