Preheat oven to 350°F. Grease a 10–12 cup Bundt pan extremely well — butter every ridge, then dust with cocoa powder (not flour, which leaves white streaks on a dark cake).

In a large bowl, whisk together the chocolate cake mix and Dutch-process cocoa until combined. Add eggs, sour cream, melted butter, water, espresso, red food coloring, and vanilla. Beat on medium speed 2 minutes, scraping the bowl once. The batter will be thick and deeply brown.

Fold in chocolate chips with a spatula until evenly distributed. Pour batter into the prepared Bundt pan. Tap the pan firmly on the counter three times.

Bake 40–45 minutes, until a thin skewer inserted in the thickest part comes out with a few moist crumbs — not wet batter. Start checking at 38 minutes. Do not overbake; this cake goes from perfect to dry quickly once the sour cream's moisture is cooked off.

Cool in pan on a wire rack for 10 minutes. Invert carefully onto the rack. Cool completely to room temperature. Wrap the cake in plastic wrap and chill the cake for at least 4 hours; it is better to do this overnight. The cold crumb accepts piped frosting without the stripes sliding, and the texture firms to the characteristic dense-yet-moist eating quality.

Make the frosting: Beat cream cheese and butter on medium-high until completely smooth and pale, 2 minutes. Add powdered sugar 1 cup at a time on low, then increase to medium-high and beat 2 minutes until stiff, bright white, and fluffy. Add vanilla and salt; beat briefly.

Transfer frosting to a piping bag fitted with a large round tip (Wilton 1A). Hold the tip slightly away from the cold cake surface. Starting 1 inch from the base, pipe thick, firm vertical stripes straight up the side all the way around. Pipe remaining frosting into the center hole.