Preheat the oven to 350 F. In a medium bowl, whisk together flour, salt, and baking soda. In a large bowl, combine butter with peanut butter and sugar until fluffy. Add in egg and vanilla extract, and mix until smooth.
Add in the flour mixture, mix until it is fully combined. Place the sprinkles into a shallow dish. Roll the cookie dough into balls, and roll each one into the sprinkles.
Place the cookies onto a large ungreased baking sheet at least 2-inches apart. Bake for 10-12 minutes. Remove from the oven, and place one chocolate kiss on each cookie.
