For the Cake:

1. 1. Preheat your oven to 350°F (175°C). Grease and line a 9-inch round cake pan with parchment paper.
   2. In a small saucepan, bring the port wine to a simmer over medium heat. Let it reduce slightly for 5-7 minutes, then remove from heat and cool to room temperature.
   3. In a medium bowl, whisk together the flour, cocoa powder, baking soda, and salt. Set aside.
   4. In a large bowl, beat together the butter and granulated sugar until light and fluffy, about 3-4 minutes.
   5. Beat in the eggs, one at a time, followed by the vanilla extract.
   6. Gradually add the dry ingredients to the wet ingredients, alternating with sour cream. Start and end with the dry ingredients, mixing until just combined.
   7. Slowly add the cooled port wine and mix until fully incorporated. The batter will be runny, but that’s fine.
   8. Pour the batter into the prepared cake pan and smooth the top. Bake for 30-35 minutes or until a toothpick comes out clean. Let the cake cool for 10 minutes before transferring to a wire rack to cool completely.
2. For the Ganache:
   1. Heat the heavy cream in a small saucepan over medium heat until it begins to simmer (don’t boil).
   2. Place the chopped dark chocolate in a heatproof bowl and pour the hot cream over it. Let it sit for 1-2 minutes before stirring until smooth.
   3. Stir in the port wine and let the ganache cool for 5-10 minutes before using.
3. Assembling the Cake:
   1. Once the cake has cooled completely, pour the ganache over the top, spreading it evenly and letting it drip down the sides.
   2. Optionally, garnish with fresh berries, chocolate shavings, or powdered sugar.
   3. Let the ganache set for 30 minutes before serving. Serve at room temperature.