Mocha Coffee Cake

Make the crumb topping:

1. In a medium bowl, combine the flour, butter, brown sugar, powdered sugar, espresso powder, and salt with a pastry blender or fork until the mixture sticks together when pressed. Chill.

Make the chocolate swirl:

1. Melt chocolate and butter in a heatproof bowl set over a pot of simmering water (water should not touch bowl) or in the top of a double boiler over medium heat. Remove pan from heat and stir in pecans, coffee, and granulated sugar. Set aside.

Make the cake:

1. Preheat oven to 350°F. Spray a 10-inch tube pan with nonstick cooking spray.
2. In a medium bowl, whisk together the flour, espresso powder, baking powder, baking soda, cinnamon, salt, and cardamom. In another medium bowl, whisk together the coffee, sour cream, and vanilla.
3. In a stand mixer fitted with the paddle attachment, or in a large bowl with an electric hand mixer, beat the butter and sugar until light and fluffy, about 3 minutes.
4. Beat in the eggs and egg yolk one at a time, mixing well after each addition. Add the dry ingredients in 3 additions, alternating with the coffee mixture in 2 additions. Scrape down the sides of the bowl as needed.
5. Spoon one-third of the batter into prepared pan; smooth the surface. Drizzle half of the chocolate swirl mixture over the batter. Add another one-third of the batter and smooth the surface. Drizzle the remaining chocolate swirl mixture over. Spoon in the remaining batter and smooth the surface. Sprinkle crumb topping over the batter and gently use your fingertips to slightly pat the crumb topping into the batter.
6. Bake cake in preheated oven until a tester inserted into the center comes out clean and cake springs back when pressed, 40–50 minutes. Let cool completely in pan on a wire rack.
7. Run a butter knife around the perimeter of pan to loosen cake. Gently invert cake onto a large plate, then return cake (crumb side up) to rack.

Glaze the cake:

1. Add the chopped chocolate into a medium mixing bowl, set aside.
2. Pour the heavy cream into a microwave safe measuring cup and microwave on high for about 1 minute or until bubbles begin to form on the surface. Take care to not overheat because the cream will boil over.
3. Pour the hot cream over the chocolate and allow it to sit for about 3 minutes. Use a small whisk to combine the mixture into a smooth chocolate glaze. Cool for about 5 minutes before stirring in the Kahlua. Drizzle over cooled cake.