* You can sub in peanut butter rather than cookie butter, but expect a completely different flavour.
** The recipe suggested that, if using a hand mixer, 6-7 minutes may be necessary. I was using a hand mixer myself and only felt the need to mix for 4-5 minutes. Use your best judgement. What you're looking for is a nicely creamed mixture without releasing any of the oils (which could result from over-mixing).
*** If the dough is tacky or too wet, add up to 2 more tablespoons of flour, for a total of 1 cup, and mix to incorporate. The flour amount may vary due to climate and variance in ingredients (moisture level of brown sugar, volume of egg, brand of Cookie Butter, etc. the flour amount could vary by a few tablespoons).
**** Do not bake with warm dough, or else the cookies will spread and bake thinner and flatter. Properly chilled dough is mandatory in this recipe!
***** Do not bake longer than 9 minutes if you want super soft and super chewy cookies - they firm up as they cool.
****** Unbaked cookie dough can be stored in an airtight container in the refrigerator for up to 5 days, or in the freezer for up to 4 months.