Preheat oven to 350 degrees F. and prepare an 8x8 pan by spraying with non-stick spray and line with parchment paper.
In a large mixing bowl add the melted butter, sugar, eggs, and vanilla and whisk until combined.
Add the cooled melted chocolate and whisk until just combined.
Add the espresso powder, flour, cocoa powder, and salt and fold with a spatula until there are no dry spots remaining.
Last, fold in the mini chocolate chips.
Add half of the brownie batter into the bottom of the prepared pan and drizzle half of the caramel sauce over the batter. Use a toothpick or butter knife to swirl the caramel into the batter. Repeat with the remaining brownie batter and top with another swirl of caramel.
Bake for 30 minutes, then remove and allow to cool completely before cutting.