Old-Fashioned Peanut Butter Cookies Ingredients 1 cup peanut butter 1 cup mayonnaise (yes! This makes them extra soft and tender) 1 large egg --- Instructions 1. Preheat Oven Heat oven to 350°F (175°C) and line a baking sheet with parchment. 2. Mix Dough In a bowl, combine peanut butter, mayonnaise, and egg. Mix until smooth and fully combined. 3. Shape Cookies Scoop tablespoons of dough, roll into balls, and place on the baking sheet. Press a fork in a crisscross pattern on top of each cookie.