Preheat oven to 375 degrees. Line two baking sheets with parchment paper.
Whisk together the flour blend, baking soda, baking powder, and salt in small bowl. Set aside.
In the bowl of a stand mixer or with an electric mixer, beat butter and peanut butter until well mixed. Slowly add both sugar and brown sugar and beat until light and fluffy, about 3 minutes.
Add the egg, milk, and vanilla and mix to combine.
Reduce the speed to low and slowly add the flour mixture just until well incorporated.
Put bowl in refrigerator for about 30 minutes.
Scoop dough with cookie scoop or small spoon and roll into balls. Dredge balls in bowl of granulated sugar and place about 2 inches apart on baking sheet.
Bake for about 8 minutes, or until puffed up. Don't overbake as they won't be as soft upon cooling.
Remove baking sheets from oven and immediate place unwrapped kiss in center of each cookie, pressing lightly. Allow cookies to cool on baking sheet for about 5 minutes and then remove to wire rack to cool completely.