Preheat oven to 325°F. Lightly grease the sides of 9-inch springform pan. Set aside.
In a large bowl, combine brownie mix, espresso powder, water, oil and egg using a sturdy spatula. Mix until there are no longer any dry streaks of brownie mix. Transfer to prepared springform pan. Spread into an even layer
Cheesecake Layer: In another large bowl (or stand mixer), beat cream cheese until smooth. Add sour cream, sugar, egg, egg yolk, vanilla, and salt. Scrape down bowl as needed to ensure thorough mixing. Continue to mix on low speed until smooth. Pour cheesecake batter into springform pan on top of brownie batter. Spread into an even layer.
Bake for 55-60 minutes until cheesecake layer is set and cake begins to pull away from the sides of the pan. Cheesecake may puff slightly but it will flatten once cooled. Let cool to room temperature, then transfer to the fridge. Let chill for at least 1 hour. Gently unmold cheesecake brownie. Slice into 12 servings using a sharp knife. Sprinkle the cheesecake generously with granulated sugar. Using a kitchen torch, burn the sugar. Let sugar cool for 3 minutes before serving.