Combine butter, oil, and chocolate in a heatproof bowl set above a saucepan of simmering water until chocolate almost fully melts, stirring gently with a spatula. Remove bowl from saucepan. Stir until chocolate fully melts. Whisk flour, cocoa powder, and salt in a bowl. In a large bowl, combine granulated sugar, brown sugar, vanilla, 1 teaspoon cinnamon, 1 tablespoon orange zest, and eggs. Beat with a mixer at medium speed until light and fluffy (about 2 minutes). Set aside 3 tablespoons of the melted chocolate mixture. Gradually pour remaining chocolate mixture in a thin stream over the egg mixture, beating at medium speed. Gently fold the flour mixture into the egg mixture. Spray 8 (6-ounce) ramekins with nonstick spray. Divide batter among ramekins. Working with one ramekin at a time, spoon a generous teaspoon of the reserved chocolate mixture into the center, pushing the teaspoon toward the center of the batter. Repeat with remaining ramekins and chocolate mixture. Arrange ramekins on a large rimmed baking sheet. Cover and refrigerate for 1 hour. Preheat oven to 400°F. Let ramekins stand at room temperature for 15 minutes. Uncover and bake for 14 to 15 minutes, or until cakes are puffy and slightly crusty on top (centers will not be set). Transfer each cake onto a plate. Sprinkle with orange zest and cinnamon. Serve immediately.