Preheat oven to 375°F.
In a large bowl, combine the flour and salt. Set aside.
Cream the butter until fluffy using an electric mixer.
Add the peanut butter and cream again.
Add the granulated sugar and brown sugar, and cream well.
Add the vanilla extract and egg yolk, mixing well after each addition.
Gradually add the flour mixture until a soft dough forms.
Let the dough sit for 10 minutes.
Color the dough with gel food dyes if desired.
Pack the dough into a cookie press and press onto an un-greased cookie sheet.
Sprinkle a little granulated sugar on the cookies.
Bake for 8 to 10 minutes until puffed and set.
Place chocolate kisses in the centers of the cookies while still warm.
Move cookies to cooling racks once kisses are placed.
