Instructions

• Preheat oven to 350°F (175°C). Line two 12-cup muffin pans with paper liners.
• In a medium bowl sift (or whisk) together 1 ¾ cups flour, ¾ cup cocoa powder, ¾ teaspoon baking soda, and ¾ teaspoon salt. Set the dry mixture aside.
• In the bowl of a mixer (or using a hand mixer), beat 1 ¾ cups sugar and ¾ cup (1 ½ sticks) butter, at room temperature, on medium speed until light and fluffy, about 2 minutes.
• Add the 2 eggs one at a time, beating well after each addition. Add 1 teaspoon vanilla and mix to incorporate.
• Add half of the dry ingredients to the butter mixture and beat on low just until combined.
• Add 1 cup hot water and mix on low just until incorporated.
• Add the remaining dry ingredients and beat on low just until blended. Do not overmix.
• Let the batter rest 5 minutes. Stir in 1 ¼ cups bittersweet chocolate chips.
• Divide the batter evenly among the lined muffin cups (about two-thirds full each). Bake for 22–25 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs.
• Cool the cupcakes in the pans for 5–10 minutes, then transfer them to a wire rack and cool completely before filling.
• To make the ganache filling and frosting: place the remaining 1 ¼ cups bittersweet chocolate chips in a heatproof bowl. Heat the 1 cup hot water until just boiling (microwave or stovetop), pour the hot water over the chocolate chips, and let stand for 1 minute. Whisk until smooth.
• Let the ganache cool at room temperature until thick and spreadable, at least 2 hours. If it is still too thin after cooling, chill briefly and stir occasionally until it reaches a spreadable consistency.
• Using your thumb, a cupcake corer, or a small spoon, press or remove a deep opening in the center of each cooled cupcake.
• Spoon ganache into each opening, reserving some ganache for frosting.
• Frost the cupcakes with the remaining ganache once it is thick enough to mound—use a spoon or small spatula to create generous peaks.
• Cupcakes may be made a day ahead and stored at room temperature.