This cake has a delicious, delicate texture a rich, deep chocolate flavor that everyone will love.
Preheat the oven and prepare the bundt pan. Preheat the oven to 325°F and adjust a rack to the center. Add 1 tablespoon of the oil to a 10 inch bundt pan and move it around so it's completely coated. (Using a pastry brush or your hands will help.) Then sprinkle 1 tablespoon of the cocoa powder in the pan and use your hands or the brush to incorporate it into the oil -- it will look like chocolate sauce. Set aside.
Combine the dry ingredients. In a large mixing bowl, combine the flour, baking soda, baking powder and remaining ⅓ cup of the cocoa powder. Stir until everything is evenly incorporated and set aside.
Combine the wet ingredients. In a medium-sized mixing bowl, whisk the eggs, egg yolks, sugar, salt and vanilla together. Once it's blended whisk in the sour cream until it's smooth. Then gradually pour in the olive oil, whisking constantly (almost like you're making a vinaigrette).
Mix the wet ingredients into the dry ingredients. Make a well in the center of the bowl with the dry ingredients and pour the combined wet ingredients into the well. (Use a rubber spatula to get every last bit.) Mix until it's completely blended together.
Add the coffee and chopped chocolate and fill the pan. Gently stir in the hot coffee or espresso, and once it's well incorporated, add the finely chopped chocolate and mix. Pour the batter into the prepared bundt pan. (Move the pan around first to be sure it's well coated with the chocolate oil, as it will likely be sitting at the bottom.)
Bake. Place the pan on a baking sheet (for easier transportation), and put it in the preheated 325°F oven. Bake only until it no longer jiggles, about 30 minutes. If you stick a sharp knife or wooden skewer into it, it should come almost, but not quite clean.
Let the cake cool in the pan for at least 10 minutes, and then invert it onto a cake platter or large plate. (Use pot holders to do this!) Continue to let it cool to room temperature.
Make the glaze. Add the finely chopped chocolate to a small mixing bowl. In a small saucepan, scald the cream with the vanilla and espresso powder. Tiny bubbles will appear on the edges of the pan and it should be very hot, but not boiling. Pour the cream over the chocolate. Do not stir it yet – wait about 4 minutes and then, gently stir to combine. It will take a few minutes of mixing before you’ll see it come together.
Add the glaze and serve. Drizzle the glaze over the cake and serve.