1. (You won't be preheating the oven just yet because the dough needs to chill. When you do, you will preheat to 350℉) – Set the vegan butter out to soften if it is cold and hard from the fridge. Chop the macadamia nuts and set aside.
3. Measure out the dry ingredients (but not the sugars) into a medium sized bowl. When you measure the flour make sure to "lighten" or sift the flour so that you aren't cramming it into the measuring cup. See the blog post for more details. Add the cornstarch, baking soda, baking powder, and salt to the flour. Mix well and set aside.
4. In a separate bowl, use a mixer to cream together the softened vegan butter with the brown sugar and the white sugar. The vegan butter should be softened but not melted. Cream until the mixture is light and fluffy and the ingredients have all been incorporated.