Gingerbread Sheet Cake With Whipped Chocolate Ganache

The gentle bite of fresh ginger and spices pairs wonderfully with bittersweet chocolate. Sticky molasses and spicy ginger flavor this warm and cozy one-bowl cake, which tastes wonderful on its own, but is even better when topped with a fluffy whipped chocolate ganache. Make sure to use chopped bars of chocolate here rather than chips, which contain stabilizers that will make the ganache grainy. The ganache will look and feel a lot like whipped cream when you spread it on the cake, but will solidify to a more mousse-like consistency when it cools.

Ingredients

• Nonstick cooking spray

• 1 ¼

  cups/250 grams granulated sugar

• 3

  large eggs

• 1

  cup/240 grams buttermilk

• ¾

  cup/255 grams unsulfured molasses

• ½

  cup/113 grams unsalted butter, melted and cooled

• ½

  cup/100 grams grapeseed or other neutral flavored oil

• 2

  tablespoons finely grated fresh ginger

• 2

  tablespoons ground ginger

• 2

  teaspoons ground cinnamon

• ½

  teaspoon ground cloves

• 1 ¼

  teaspoons kosher salt (Diamond Crystal)

• 2 ½

  cups/320 grams all-purpose flour

• 1 ½

  teaspoons baking powder

• ½

  teaspoon baking soda

Preparation

1. Make the cake: Set a rack in the center of the oven and heat oven to 350 degrees. Grease a 9-by-13-inch light colored metal baking pan with nonstick cooking spray and line it with a piece of parchment that hangs over the 2 long sides. 
2. In a large bowl, combine the sugar and eggs, and use an electric mixer on medium or a whisk to beat the mixture until light and foamy, 1 to 2 minutes. Add the buttermilk, molasses, butter and oil, and mix until combined and smooth, 1 to 2 minutes.
3. Add the fresh ginger, ground ginger, cinnamon, cloves and salt, and mix to incorporate. 
4. Add the flour, baking powder and baking soda, and mix until no streaks of dry ingredients remain, about 1 minute.
5. Pour the batter into the prepared baking pan, and tap on the counter a few times to release any large bubbles. Bake until puffed and set, and a tester inserted into the center comes out clean, 28 to 34 minutes. Cool the cake in the pan set on a rack for 15 minutes, then use the parchment paper overhang to lift the cake out of the pan. Set it on a rack to cool completely.
6. While the cake is cooling, make the ganache: Add the chocolate and butter to a large bowl or to the bowl of a stand mixer fitted with the whisk attachment. In a small saucepan, bring the cream to a simmer.
7. Pour the hot cream over the chocolate and butter in the bowl, and whisk until smooth, 1 to 2 minutes. Add the vanilla extract and salt, and whisk until incorporated. Let the mixture sit until slightly thickened, about 1 hour.
8. When the cake is cool and the ganache is thickened, whip the ganache on high speed until it’s lighter in both texture and color, fluffy, and holds soft peaks, about 10 minutes.
9. Dollop the ganache over the cooled cake, and use a spoon to spread it over the cake in swoops and swirls. Top with chopped crystallized ginger or shaved chocolate if desired. Store leftover cake in an airtight container in the fridge for up to 4 days.