Preheat oven to 375 degrees F. Line a baking sheet with parchment paper and set aside.
In a medium bowl, whisk together the flour salt and baking powder.
In large bowl mixing bowl combine the butter, shortening and peanut butter and beat until smooth. Pour in the brown sugar and mix until smooth. Scrape down sides and bottom of the bowl. Blend again
Add the egg and vanilla and blend until the yolk disappears. Slowly add the flour mixture and blend on low until incorporated. Scrape down the sides of the bowl and blend another 30 seconds.
Shape dough into small 1-inch balls(about 12g each); roll in granulated sugar and place on the prepared cookie sheet at least 1-inch apart.
Bake 9 to 12 minutes until light golden brown on the bottom.
Remove from oven; immediately top each cookie with a milk chocolate candy kiss, pressing down firmly so the cookie lightly cracks around edge.
Allow the cookies to sit on the pan or parchment for 5 minutes then remove to a wire rack to cool completely.
Wait until the chocolate kisses have hardened before storing in an airtight container.