Cookie Butter Brown Sugar Cookies

1.To the bowl of a stand mixer fitted with the paddle attachment (or large bowl and electric hand mixer), cream together the egg, Cookie Butter, brown sugar, and vanilla on medium-high speed until light and fluffy, about 4 to 5 minutes. Do not shortchange this creaming step, and if using a hand mixer, 6-7 minutes may be necessary. Don't overbeat or overdo it so that the oils start releasing; just make sure the mixture is properly creamed.
2.Stop, scrape down the sides of the bowl, and add flour, cornstarch, cinnamon, baking soda, salt, and mix on low speed until just incorporated, about 1 minute; don't overmix. The dough will be soft and on the oily side, but it should come together and not be sticky, tacky, or wet. Then cover with plastic wrap and refrigerate dough for at least 3 hours, or up to 5 days. Do not bake with warm dough because cookies will spread and bake thinner and flatter. Properly chilled dough is mandatory.
3.Preheat oven to 350F, line a baking sheet with a Silpat, or spray with cooking spray. Using a medium 2-inch cookie scoop, form heaping two-tablespoon mounds. Place mounds on baking sheet, spaced at least 2 inches apart (bake 8 cookies per sheet) and flatten each one slightly. Bake for 8 minutes, or until edges have set and tops are just beginning to set, even if slightly undercooked, pale and glossy in the center. Do not bake longer than 9 minutes if you want Softbatch-style cookies because they firm up as they cool. Allow cookies to cool on the baking sheet for about 5 minutes before removing and transferring to a rack to finish cooling.
4.Store cookies airtight at room temperature for up to 1 week, or in the freezer for up to 4 months. Alternatively, unbaked cookie dough can be stored airtight in the refrigerator for up to 5 days, or in the freezer for up to 4 months, so consider baking only as many cookies as desired and save the remaining dough to be baked in the future when desired.