• Preheat the oven to 350°F
• Prepare the (2) 8x4 loaf pans by either greasing and flouring or lining them with parchment paper.
• Beat together the brown sugar and granulated sugar together with butter until smooth.
• Add eggs one at a time including the egg yolk and add the vanilla extract.
• In a separate bowl, combine flour, baking powder, and salt.
• Gently beat in the dry ingredients until moistened.
• Stir in the sour cream.
• Divide the batter into two equal parts and place each batter half in a separate bowl.
• Stir in the unsweetened cocoa, instant coffee granules, and sour cream into one bowl of batter. Mix until the cocoa is all moistened and it is blended well.
• Combine the canned pure pumpkin together with flour, cinnamon, cloves, nutmeg, and ginger. Stir the pumpkin spice batter into the remaining bowl of batter.
• Using a spoon, spoon a large spoonful of chocolate batter into the prepared pan. Using a separate spoon, spoon a large spoonful of pumpkin spice batter into the pan next to the chocolate batter.
• Continue alternating the batter until the bottom of the pan is covered.
• Repeat the process with the other pan, and if any batter is leftover, divide equally among the two pans.
• Use a butter knife to swirl or create a figure eight into the tops of the pans before baking.
• Bake for 55-60 minutes. Check the center of the cakes with a toothpick to ensure it is done baking. If needed, bake for a few more minutes.
• Allow the cake to cool for 15 minutes before removing it from the pans to cool completely.

Make the ganache

• Add the chocolate chips to a heat-proof bowl and set it aside.
• Heat the heavy cream in a saucepan over medium-low heat.
• Once it comes to a simmer and is barely bubbling, pour the heavy cream over the chocolate chips.
• Allow the bowl to sit for 5 minutes before stirring the heavy cream into the chocolate chips.
• Allow the mixture to cool and thicken before pouring onto the cakes.