Nutella and espresso on a brownie stage, living it up! This will be the new family dessert.
For the brownie layer
  1. Preheat oven to 350º.
  2. Line the bottom of 8-inch square baking dish with parchment, leaving several inches overhang on two sides- set aside.
  3. Melt the butter in a large bowl. Whisk in the espresso powder until it dissolves completely, then whisk in the sugar.
  4. Add the eggs, one at a time, whisking well after each addition. Stir in the vanilla.
  5. Mix in the dry ingredients until just mixed.
  6. Pour into the prepared pan and bake for 30 minutes, until a toothpick inserted in the center comes out with a few crumbs.
  7. (Allow to cool completely before topping with the mousse.)
  8. To make the mousse, combine the espresso and hot water in a small bowl.
  9. Whisk in Nutella.
  10. Using a stand mixer, beat heavy cream until it just forms stiff peaks.
  11. Gently fold in the Nutella mixture. Scrape the mousse onto the top of the cooled brownies and spread evenly.
  12. Refrigerate for at least an hour or up to overnight.
  13. Using the parchment, lift the brownies from the pan.
  14. Cut into squares and top with chocolate curls.
  15. Serve immediately.