Ingredients:

  • 1 cup unsalted butter, room temperature
  • 1 cup dark brown sugar, packed
  • 0.25 cup granulated sugar
  • 1 large egg, room temperature
  • 2 tbsp dark molasses
  • 1 tbsp vanilla extract
  • 1.5 cups all-purpose flour
  • 3 cups quick-cooking oats
  • 1 tsp baking soda
  • 1 tsp ground cinnamon
  • 0.5 tsp salt
  • 0.5 cup unsalted butter, softened
  • 2 cups powdered sugar, sifted
  • 0.5 cup marshmallow crème
  • 1.5 tbsp heavy cream

Instructions:

  1. Preheat your oven to 175°C (350°F). Line two large baking sheets with parchment paper. Note: This ensures the cookies don't stick and brown evenly.
  2. Cream the 1 cup of softened butter, dark brown sugar, and granulated sugar together on medium-high for 3 minutes until the mixture is pale and fluffy.
  3. Add the egg, molasses, and vanilla extract, beating until fully incorporated and the batter looks like mahogany silk.
  4. In a separate bowl, whisk together the flour, baking soda, cinnamon, and salt. Gradually add the dry ingredients to the wet mixture, then fold in the quick-cooking oats until just combined.
  5. Using a medium cookie scoop (2 tbsp capacity), drop portions of dough onto parchment-lined baking sheets, spacing them 5 cm apart.
  6. Bake for 10 minutes. Remove when the edges are just set but the centers still look slightly damp. Let cool on the pan for 5 minutes. The cookies will firm up as they sit; removing them too early will cause them to shatter.
  7. Prepare the filling by beating 0.5 cup butter, powdered sugar, marshmallow crème, and heavy cream until light and cloud-like.
  8. Match cookies by size. Pipe or spoon a generous amount of filling onto the flat side of one cookie and top with a second cookie to form a sandwich. Press gently until the cream reaches the edges.