Preheat the oven to 350ºF. Line three 9-inch round cake pans with parchment paper and lightly spray with non-stick baking spray. In a 3-quart saucepan, combine the butter, oil, chopped chocolate, and water over medium heat until melted. Whisk in the espresso powder.
In a large bowl, whisk together the flour, sugar, and cocoa powder. Pour the hot chocolate mixture into the sugar mixture and whisk until combined. Whisk in the eggs, one at a time, then whisk in the buttermilk, vanilla, baking soda, and salt. Evenly divide the batter between the prepared pans. Bake until a toothpick inserted in the center comes out clean, about 35-40 minutes. Cool on the rack for 10 minutes, then invert onto the racks, remove parchment and cool completely. (Cakes can be made one day ahead wrapped in plastic wrap at room temperature, or freeze for up to one month).
For the Frosting
In a 4-quart saucepan over low heat, combine the cream, butter, vanilla bean, and seeds. Stir until the butter is melted. Remove the vanilla bean and whisk in the chopped chocolate. Whisk in the sugar, cocoa powder, syrup, espresso powder, and salt; making sure the cocoa powder is dissolved. Strain the frosting through a fine-mesh sieve set over a 9 x 13-inch pan. Freeze until firm, about 2 hours, or refrigerate overnight. (Frosting can be refrigerated for up to three days)