In a large mixer bowl beat butter and peanut butter with an electric mixer on medium speed for about 30 sec or until combined.
Add the sugars and beat until fluffy. Then, beat in the egg, milk and vanilla.
In a separate small mixing bowl stir together flour, baking powder, salt and baking soda. With mixer on low speed gradually add flour mixture to peanut butter mixture. Cover and chill about 1 hour for easier handling.
Preheat oven to 375 degrees. Shape dough into 1 inch balls. Roll in additional sugar. Place about 2 inches apart on ungreased cookie sheets.
Bake for 10-12 minutes or till edges are firm. Immediately press a hershey's kiss on top of each cookie. Then, move to a wire rack to cool.
Please note, Holiday Sweets N Treats isn't a professional nutritionist. Any and all nutritional information shared is an estimate. If you're following a specific diet or counting calories, we suggest you use the nutrition calculator of your choice. Calories can vary depending on the brands and products used.