The original recipe appeared as Aunt Patty's Coffee Cake in Mad Hungry: Feeding Men and Boys by Lucinda Scala Quinn. Makes 1 Bundt cake; serves 12-20.
2 Tbsp + 1 cup sugar sugar
1 Tbsp instant espresso
1 Tbsp unsweetened cocoa powder
2 cups unbleached all-purpose flour
1 tsp baking soda
1 tsp baking powder
1-1/2 tsp kosher salt
8 Tbsp (1 stick) unsalted butter, softened to room temperature
2 large eggs, at room temperature
1 cup + 1 Tbsp sour cream or Greek yogurt, at room temperature
1 tsp pure vanilla extract
Preheat oven to 350°F. Coat the inside of a 12-cup Bundt pan with baking spray, and set aside.
In a small bowl, mix together 2 tablespoons of sugar with the instant espresso and cocoa powder.
In a large bowl, whisk together the flour, baking soda, baking powder and salt.
In the bowl of a stand mixer, cream the butter and 1 cup of sugar, until well incorporated. Add the eggs, one at a time, beating until just combined. Then, with the mixer set on the lowest speed, incorporate one third of the flour mixture, half of the sour cream or yogurt, then another third of the flour. Beat in the remaining sour cream, and the last third of the flour. Add the vanilla and mix for another minute or two, scraping down the sides of the bowl with a spatula as needed.
Now, fill the Bundt pan: Take one-third of the batter, and distribute it evenly in the pan. The batter will be thick, so it will take a big of work with a spatula to spread it. Sprinkle half of the espresso-cocoa filling mixture on top. Then, layer into the pan half the remaining batter, followed by all of the remaining filling, and the final bit of the batter. Take a knife and swirl it down through the batter in a few places.
Bake in the middle of the oven for 50 minutes, or until a cake tester (or large skewer) inserted in the thickest part comes out clean. Cool on a rack for 30 minutes, and serve, or wrap in aluminum foil and freeze (you can do this while the cake is still warm).