Peanut Butter-Cinnamon Cookies
["1/2 c. butter, softened", "1/2 c. creamy peanut butter", "1/2 c. sugar", "1/2 c. firmly packed brown sugar", "1 egg", "1 tsp. vanilla", "1 1/4 c. flour", "1/2 tsp. soda", "1/2 tsp. salt (optional)", "1 tsp. cinnamon"]
["Cream butter and peanut butter; gradually add sugar, beating until light and fluffy.", "Add egg and vanilla and beat well."]
["butter", "peanut butter", "sugar", "brown sugar", "egg", "vanilla", "flour", "soda", "salt", "cinnamon"]