Peanut Butter Snickerdoodles

Step 1
Preheat the oven to 375 degrees F (190 degrees C).

Step 2
Combine peanut butter, 1 cup white sugar, brown sugar, butter, and shortening in a large bowl. Beat with an electric mixer until creamy. Stir in vanilla extract. Beat in eggs.

Step 3
Sift flour, cream of tartar, 1 1/2 teaspoons cinnamon, baking soda, baking powder, and salt together in a separate bowl. Gradually add to the egg mixture and mix well.

Step 4
Mix 1/4 cup sugar and 2 teaspoons cinnamon together in a shallow bowl. Roll dough into 1-inch balls, roll in cinnamon-sugar, and place on a baking sheet. Flatten each ball slightly with the bottom of a drinking glass, or by making a criss-cross pattern with the tines of a fork.

Step 5
Bake in the preheated oven until slightly browned, about 8 minutes. Do not overbake. Transfer to a wire rack to cool.