Makes about 4 dozen cookies.

Ingredients

  • 1/2 cup unsalted butter, very soft
  • 1 1/2 cups creamy peanut butter
  • 1 cup brown sugar
  • 1/4 cup white sugar
  • 3 eggs
  • 2 teaspoons vanilla
  • 4 1/2 cups old-fashioned oats, certified gluten-free if the cookies need to be gluten-free 
  • 2 teaspoons baking soda
  • 1/2 teaspoon salt
  • 2 cups chocolate chips
  • One 14-ounce can sweetened condensed milk

Directions

  1. Preheat oven to 350°F and line two large cookie sheets with parchment paper.
  2. In a large bowl, mix the butter, peanut butter, and sugars. (You can use beaters, but it's easiest to just vigorously mix by hand.) Mix in eggs and vanilla until thoroughly incorporated. Add the oats, baking soda, and salt, and mix thoroughly. Refrigerate the dough while preparing the fudge topping.
  3. Mix the chocolate chips and sweetened condensed milk in a small saucepan. Warm over low heat, stirring frequently, until the chocolate is completely melted. Stir vigorously to make sure the mixture is evenly mixed. Turn off the burner under the chocolate.
  4. Remove the dough from the refrigerator and roll half of it into walnut-sized balls, pressing each one semi-flat on the cookie sheet. Top each ball of dough with a teaspoon of the warm chocolate mixture.
  5. Bake the cookies for 10 minutes or until just golden around the edges. Remove from the oven and let cool on the sheets for a few minutes until they have firmed up enough to remove to wire racks. (You can remove the entire sheet of parchment paper and move the cookies to the rack in that way.)
  6. Repeat with the remaining dough and fudge topping. (Warm and stir the chocolate over low heat if it has hardened too much to scoop.) Store the cooled cookies in an airtight container for up to 5 days.