Chewy Chocolate Toffee Marshmallow Cookie Bars

Adapted from
Makes 12 -18 bars
Author Wendy Sondov


  • 2 cups all-purpose flour
  • ½ teaspoon baking soda
  • ¾ cup 1 ½ sticks salted butter, melted and cooled
  • 1 cup brown sugar I use dark brown
  • ½ cup granulated sugar
  • 1 egg + 1 egg yolk room temperature
  • 2 teaspoons vanilla extract
  • 1 cup chocolate chunks
  • ½ cup heath toffee bits I use the chocolate covered bits
  • ¾ cup marshmallow creme


  1. Pre-heat oven to 350 degrees F. Butter and lightly flour a 9”x 13” baking pan.
  2. In a large bowl, whisk together the flour and baking soda.
  3. In the bowl of the electric mixer, combine the butter and sugars.
  4. Add the egg, egg yolk, and vanilla and beat until fluffy.
  5. Gradually add the flour mixture, mixing until combined and a crumbly dough forms.
  6. Fold in the chocolate chunks and toffee bits.
  7. Barely fold in marshmallow fluff, leaving stripes of fluff visible in the dough.
  8. Press the dough into the baking pan, spreading evenly.
  9. Bake for 25 minutes then cover loosely with foil and bake an additional 5-10 minutes until the edges are golden brown.
  10. Cool for 30 minutes in the pan and then cut into bars. For flat, even bars trim outside edges before cutting into bars.
  11. Store in an airtight container at room temperature for up to 1 week.

Packing Tips

Wrap the bars individually (or in pairs) in plastic wrap before storing in an airtight container (or zip lock bag) at room temperature for up to 1 week. Though the bars still taste good after 1 week, they tend to dry out and become less chewy.