For the Cake:

1. 1. Preheat your oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.
   2. In a small saucepan, bring the port wine to a simmer over medium heat. Let it reduce slightly for about 5-7 minutes, then remove from heat and cool to room temperature.
   3. In a medium bowl, whisk together the flour, ground hazelnuts, cocoa powder, baking powder, baking soda, and salt. Set aside.
   4. In a large bowl, beat together the softened butter and sugar until light and fluffy, about 3-4 minutes.
   5. Add eggs one at a time, beating well after each addition. Stir in vanilla extract.
   6. Gradually add the dry ingredients to the wet ingredients, alternating with the milk. Start and end with the dry ingredients. Mix until just combined.
   7. Stir in the hot water. The batter will be thin, but this will ensure a moist cake.
   8. Gently fold in the chopped hazelnuts.
   9. Divide the batter evenly between the prepared cake pans and bake for 25-30 minutes or until a toothpick inserted comes out clean. Let cool in the pan for 10 minutes, then remove and transfer to a wire rack to cool completely.
2. For the Ganache:
   1. In a small saucepan, heat the heavy cream over medium heat until it just starts to simmer (do not boil).
   2. Place chopped dark chocolate in a heatproof bowl. Pour the hot cream over the chocolate and let sit for 2-3 minutes. Stir until smooth.
   3. Stir in the butter until the ganache is glossy and smooth. Allow it to cool for 5-10 minutes before using.
3. Assembling the Cake:
   1. Once the cakes have cooled completely, place one layer on a serving plate. Spread a generous layer of ganache over the first layer.
   2. Top with the second cake layer and cover with the remaining ganache. Let the ganache set for about 15 minutes.
   3. Optional: Garnish with chopped hazelnuts or a dusting of cocoa powder for decoration.
   4. Allow the ganache to fully set before serving. Serve at room temperature and enjoy!