Alittle unsweetened cocoa powder in the topping and batter goes a long way to transform a classic crumb cake into a deeply chocolaty treat (that’s still tame enough for breakfast). Raw, unsalted pistachios add a gleam of color and complementary flavor to the crumb.

Ingreadients:

FOR THE CRUMB:

•  1 ³⁄₄ cups all-purpose flour (218 g)
•  1 cup firmly packed organic light-brown sugar (200 g)
•  ¹⁄₄ cup natural cane sugar (48 g)
•  ¹⁄₄ cup unsweetened cocoa powder (25 g)
•  2 tsp. ground cinnamon
•  1 ¹⁄₄ tsp. kosher salt
•  1 cup plus 2 Tbsp. (2¼ sticks) unsalted butter, cut into medium-size cubes, then left out to soften
•  ¹⁄₂ cup bittersweet chocolate chips (65 g)
•  ¹⁄₄ cup coarsely chopped raw unsalted pistachios (35 g)

FOR THE CAKE:

•  2 ¹⁄₄ cups all-purpose flour
•  ¹⁄₂ tsp. baking powder
•  ¹⁄₂ tsp. baking soda
•  ³⁄₄ tsp. kosher salt
•  ³⁄₄ cup plus 2 Tbsp. (1¾ sticks) unsalted butter, softened, plus more for greasing
•  1 ¹⁄₂ cups natural cane sugar
•  3 large eggs
•  2 tsp. pure vanilla extract
•  1 cup full-fat sour cream
•  5 tbsp. unsweetened cocoa powder
•  ¹⁄₄ tsp. espresso powder

Direction

1. Make the crumb: In a large bowl, add the flour, both sugars, the cocoa powder, cinnamon, and salt; stir. Add the butter; mix it in with your fingers and by squeezing with your palms until it feels saturated and chunky, 3–4 minutes (you will crumble it later). Refrigerate until firm, at least 25 minutes, or until ready to bake the cake.
2. Preheat the oven to 350°F and set a rack in the center. Meanwhile, mix the cake: In a large bowl, add the flour, baking powder, baking soda, and salt; stir briefly to combine. In the bowl of a standing mixer fitted with the paddle attachment, beat the butter and sugar at medium-high speed, scraping down the sides of the bowl as needed, until light and fluffy, about 3 minutes. Add the eggs and vanilla, and beat at medium-low speed, scraping down the bowl as needed, until incorporated. With the mixer on low, alternate adding the flour mixture (in three batches) and the sour cream (in two batches), beginning and ending with the flour mixture, and beating until just incorporated.
3. Transfer one-third of the batter (about 365 g) into a separate bowl. Add the cocoa and espresso powders, and 2 tablespoons of cool water, and stir with a spatula until just combined.
4. Grease a 9x13-inch cake pan or baking dish with butter. Add the white batter, and use an offset spatula to spread it evenly into a thin layer, filling the corners. Add the chocolate batter in large dollops all across the top, and create a marbling pattern.
5. Retrieve the crumb topping (it should be fully solid). Add the chocolate chips and pistachios; mix well. Crumble the topping evenly over the batter in pebble-size pieces.
6. Bake until the cake no longer jiggles when moved and a toothpick inserted into the center comes out mostly clean, 50–55 minutes. Remove and let cool completely before slicing.