📖 Instructions

1. Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan. Don't skip the flouring, unless you want cake-astrophy! (See what I did there?).
2. In a medium bowl, whisk together 2 cups all-purpose flour, ¾ cup unsweetened cocoa powder, 1 ½ teaspoons baking powder, 1 ½ teaspoons baking soda, and ¾ teaspoon salt. Ensure there are no clumps of cocoa powder; nobody wants a mouthful of that.
3. In a large bowl, cream together 1 cup (2 sticks) unsalted butter, softened, and 1 ¾ cups granulated sugar until light and fluffy. This might take a few minutes, so put on some music and get into it.
4. Beat in 3 large eggs, one at a time, then stir in 2 teaspoons vanilla extract. Make sure each egg is fully incorporated before adding the next. We're not making scrambled eggs here, folks.
5. In a small skillet, sauté 8 ounces of cremini mushrooms, finely diced, in 2 tablespoons of unsalted butter until softened and lightly browned. Stir in 1 tablespoon of truffle oil. Let cool slightly. The truffle oil really brings the mushrooms to life!
6. In a separate bowl, combine 1 cup of hot coffee and ½ cup of buttermilk. I know, coffee and buttermilk sounds strange, but trust the process!
7. Gradually add the dry ingredients to the wet ingredients, alternating with the coffee mixture, beginning and ending with the dry ingredients. Mix until just combined. Be careful not to overmix; a few streaks of flour are okay. Overmixing leads to tough cake, and nobody wants that.
8. Gently fold in the sautéed mushrooms. Make sure they're evenly distributed throughout the batter. Each bite should have a hint of mushroomy goodness.
9. Pour the batter into the prepared cake pan and bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out with moist crumbs attached. Check it after 30 minutes; ovens vary, and we don't want a dry cake.
10. Let the cake cool in the pan for 10 minutes before inverting it onto a wire rack to cool completely. Patience is a virtue, especially when it comes to cooling cake.
11. While the cake is cooling, prepare the chocolate ganache. In a heatproof bowl set over a saucepan of simmering water (or in the microwave in 30-second intervals), melt 12 ounces of semi-sweet chocolate chips with ¾ cup heavy cream, stirring until smooth. Stir in 1 tablespoon of truffle oil. The aroma at this point is simply divine.
12. Once the cake is completely cool, pour the chocolate ganache over the top, allowing it to drip down the sides. You can also use a spatula to spread it evenly. Get creative!
13. Garnish with a sprinkle of cocoa powder and a few thinly sliced fresh mushrooms, if desired. It adds a touch of elegance. This is truly the time to enjoy and eat.