Ingredients:

  • 1 box (15.25 oz) Duncan Hines yellow cake mix
  • 113g Unsalted Butter, melted and cooled
  • 2 Large Eggs, room temperature
  • 120g Full fat Sour Cream
  • 1 tsp Pure Vanilla Extract
  • 1/4 tsp Espresso powder
  • 255g Semi sweet chocolate chips
  • 1/2 tsp Flaky sea salt

Instructions:

  1. Preheat your oven to 175°C. Line your 9x13 pan with parchment paper, leaving an inch of overhang on the sides.
  2. Melt the 113g of butter in a small bowl. Let it sit for 5 minutes until it’s warm to the touch but not sizzling hot.
  3. In a large bowl, whisk the 2 eggs, 120g sour cream, vanilla, and espresso powder until smooth.
  4. Slowly pour the cooled butter into the egg mixture while whisking constantly.
  5. Dump the entire box of yellow cake mix into the wet ingredients.
  6. Using your spatula, fold the dry mix into the wet until just combined. Stop when you see no more white streaks. Over mixing at this stage will make the bars tough.
  7. Gently fold in 200g of the chocolate chips, saving the remaining 55g for the top.
  8. Transfer the thick batter to the prepared pan. It will be sticky! Use the back of a damp spoon to press it into the corners.
  9. Sprinkle the remaining chocolate chips and the 1/2 tsp of flaky sea salt over the surface.
  10. Slide the pan onto the center rack. Bake for 25 minutes until the edges are golden and the center is set but still slightly soft to the touch.