• Prepare a 12-cup Bundt pan by generously spraying the inside with non-stick baking spray or melted butter. Lightly dust with flour.
• Preheat oven to 325℉ (163℃)

Mocha Filling

• Combine brown sugar, espresso powder and chocolate chips in a bowl. Set aside for later.
  ⅓ Cup Light Brown Sugar, 2 teaspoons Espresso Powder, ½ Cup Chocolate Chips, bittersweet

Cake Batter

• Mix eggs, yolks and sour cream together in a bowl. Set aside for later.
  2 Large Eggs, 2 Large Egg Yolks, 1 Cup Sour Cream
• Place sugar, flour, baking powder and baking soda in the bowl of a stand mixer fitted with the paddle attachment. Mix on medium-low speed until ingredients are combined. Note: a hand mixer may also be used.
  2 Cups All-Purpose flour, 1 Cup Granulated Sugar, 1 teaspoon Baking Powder, 1 teaspoon Baking Soda
• Add softened butter to mixing bowl. Mix on low speed for 3 minutes. Mixture will appear crumbly.
  10 Tablespoons Butter
• Add half of the egg/sour cream mixture to the mixing bowl and combine on low speed for one minute. Scrap sides of bowl.
• Add remaining egg/sour cream mixture to the mixing bowl. Combine on low speed for one minute. Scrape sides of bowl and mix on low speed for another minute.
• Add ½ of the cake batter to the prepared pan and smooth with a rubber spatula.
• Using the back of a spoon, carve a shallow tunnel through the center of the cake batter—this will hold the mocha filling.
• Pour the chocolate, espresso, and brown sugar mixture into the tunnel you just created in the cake batter. Then spoon the remaining batter over the top and gently smooth it out with a rubber spatula.
• Bake for 50 minutes or until top is quite brown and a toothpick inserted in the center comes out clean.
• Remove pan from oven and cool upright for 10 minutes.
• Flip pan upside down onto a cooling rack and let cool completely. Remove pan - cake should release from pan on its own. If not, use blunt knife and gently loosen sides.

Coffee Drizzle

• Mix powdered sugar and espresso together until smooth. Use a pastry bag or spoon to drizzle over cake.
  1 Cup Powdered Sugar, 2 Tablespoons Brewed Espresso