In a small bowl, whisk flour, baking and salt. Set aside.
In a large bowl, using an electric mixer, cream together butter and sunflower butter until blended.
Gradually add granulated sugar and brown sugar to sunflower butter mixture - cream well. Add egg and vanilla - beat well.
Blend in dry ingredients gradually (Note: I do this step by hand using a wooden spoon) and mix thoroughly. Chill dough in the refrigerator for at least 2 hours (Note: I typically chill overnight).
Preheat oven to 375 degrees. Line baking sheets with parchment paper.
Shape dough into balls using a rounded teaspoonful for each. Roll balls in granulated sugar and place on baking sheet.
Bake for 8 minutes. Remove from oven. Top each cookie with a Hershey's Kiss candy, pressing down firmly so cookie cracks around edge. Return to oven and bake 2 to 5 minutes longer until golden brown. Move cookies to wire rack to cool completely.
Recipe by Alida's Kitchen at https://www.alidaskitchen.com/2012/11/08/sunny-blossoms/