In a small bowl, whisk the espresso powder with 1/2 cup hot water. Reserve 2 tablespoons of the espresso liquid. Whisk the condensed milk into the remaining espresso liquid.
In a baking dish, whisk together the eggs, cream, salt and reserved espresso liquid. Add the bread slices to the dish and turn to coat.
In a large nonstick skillet or griddle, melt 2 tablespoons butter over medium heat. Add 4 slices bread and cook, turning once, until golden-brown, about 5 minutes. Repeat with the remaining 2 tablespoons butter and 4 slices bread. Serve warm, drizzled with the espresso cream.