Another cookie that people either totally love or totally hate. If you're a peanut butter cookie lover, you will flip for these, developed by pal David Bonom, who gave them their name too. When we asked him why he named them so, he answered "I love these cookies and I love Liam!" Why shortening? While the purists among you may want to substitute butter for the shortening, be prepared for your peanut butter cookies to have a totally different texture—they'll be soft and sandy rather than crisp and chewy. Also, be sure to combine the flour, baking powder, and salt in a separate bowl before adding to the peanut mixture. This extra step avoids over-mixing the batter, which results in tougher cookies. It is also done to make sure the leavening is distributed evenly in the batter.
Place the shortening, sugars, peanut butter, egg, and vanilla in the bowl of a mixer fitted with a paddle and beat on medium speed stopping occasionally to scrape down the sides of the bowl, until well combined, about 3 minutes.
In a separate bowl, combine the flour, baking powder, and salt. Add the flour mixture to the peanut butter mixture and beat on low speed until well combined, 1 to 2 minutes. Add the peanuts and beat 30 seconds longer.
Drop the batter by tablespoonfuls on the prepared cookie sheets, about 1 1/2 inches apart. Roll each tablespoon of batter into a ball. Working one at a time, dip the tines of a fork in sugar and press down each ball into a 1 1/2- to 1 3/4- inch round, forming a crosshatch on top.
Transfer to the oven and bake until the edges of the cookies are lightly browned, 12 to 14 minutes. Cool cookies on cookie sheet on a rack for 5 minutes. Transfer to the rack and cool completely.