This is the best peanut butter cookie I've ever made.
From Betty Crocker's Cookbook

1/2 c. white granulated sugar
1/2 c. packed brown sugar
1/2 c. peanut butter
1/4 c. shortening
1/4 c. butter, softened
1 egg
1 1/4 c. flour
3/4 tsp. baking soda
1/2 tsp. baking powder
1/4 tsp. salt

Mix sugars, peanut butter, shortening, butter and egg.
Stir in remaining ingredients.
Cover and refrigerate for 2-3 hours.

Heat oven to 375 degrees.
Roll dough into balls.
Place on cookie sheet.
Flatten in a crisscross pattern with a fork dipped in white sugar.

Bake 9-10 minutes, until just lightly browned.
Cool a couple minutes and then remove from cookie sheet.
Makes about 3 dozen cookies.