Ingredients
Unsalted butter, softened, for pan
3/4 cup unsweetened cocoa powder, plus more for dusting
1 1/2 cups all-purpose flour
1 1/2 cups sugar
1 1/2 teaspoons baking soda
3/4 teaspoon baking powder
3/4 teaspoon salt
2 large eggs
3/4 cup buttermilk
1/4 cup vegetable oil
1 teaspoon vanilla extract
1 bag of chocolate chips (approximately 24 ounces)
1 carton of chocolate-chip ice cream (approximately 1.5 quarts)
1 peanut-butter cup, for decoration (optional)
4 to 6 mini sandwich cookies, for decoration (optional)
Blue sanding sugar, for decoration
Whipped cream, for decoration
Preparation
Preheat oven to 350 degrees. Butter a 10-by-5 1/2-inch loaf pan. Dust with cocoa powder; tap out excess. Sift cocoa powder, flour, sugar, baking soda, baking powder, and salt into the bowl of an electric mixer fitted with the paddle attachment.
Add eggs, 3/4 cup warm water, the buttermilk, oil, and vanilla. Mix on low speed until smooth, about 3 minutes. Raise speed to medium; mix 30 seconds.
Transfer batter to prepared pan. Bake until a cake tester inserted into center comes out clean, about 1 hour. Let cool in pan on a wire rack 15 minutes. Run a knife around edges to loosen; invert, and unmold. Let cool completely, right side up. Wrap in plastic. Refrigerate until cold, about 2 hours (or up to 2 days).
Cut chocolate loaf cake into three layers; place one in a loaf pan lined with plastic wrap. Peel paper off container of chocolate-chip ice cream and cut 1-inch-thick slices. Lay slices on cake, cutting to fit; fill in holes with ice-cream pieces. Add another layer of cake and ice cream; cover with remaining cake. Press down lightly and refreeze (at least 3 hours).
Trim cake to create bow and stern. Press on chocolate chips to cover top of ship. Attach mini sandwich cookies to sides of ship. Refreeze (up to 5 hours).
Attach mast (see Cook’s Note below) before serving. Pipe whipped cream waves at base of cake just before serving, and sprinkle with blue sanding sugar.
