Preheat oven to 350°F. Line two baking sheets with parchment paper.
Cream butter, cookie butter, brown sugar, and granulated sugar until light and fluffy, about 2 minutes.
Beat in vanilla, egg, and egg yolk until smooth.
Whisk flour, cornstarch, baking soda, salt, and cinnamon in a bowl.
Add dry ingredients to the wet mixture and mix on low just until a soft dough forms.
Chill the dough for 20 minutes to firm slightly for easy scooping.
Scoop 1½-tablespoon portions, roll into balls, and set on sheets 2 inches apart. Gently flatten the tops.
Bake 9–11 minutes, until edges are set and centers look slightly underdone.
Cool on the sheet 5 minutes, then transfer to a rack to finish cooling.