In large bowl, cream butter and SunButter together until smooth.
Add sugars and cream for 2-3 minutes.
Add egg, beating until combined.
Stir in flour, baking soda, and baking powder until dough forms.
Shape dough into 1-inch balls. Roll in additional sugar.
Place balls about 2 inches apart on ungreased cookie sheets.
Bake 8 to 10 minutes until edges are light golden brown. Immediately press 1 Kiss candy in the center of each cookie.
Remove from cookie sheets to cooling rack
Notes
Sometimes, the natural chorophyll contained in sunflower seeds reacts with baking soda and baking powder in the recipe, cuasing a green color in the cookies after they cool. This is harmless. Depending on the recipe, you can reduce the baking soda/powder by about one-third or add a splash of lemon juice to help prevent any “greening”.