Cinnamon Sheet Cake with Cider Frosting
Servings: One 9-by-13-inch cake (18 servings)
Cinnamon Sheet Cake
½ cup (110g) vegetable oil, or other neutral oil
1 cup (198g) granulated sugar
½ cup (106g) light brown sugar
4 tablespoons (57g) unsalted butter, melted
3 large (170g) eggs
1 tablespoon pure vanilla extract
2½ cups (301g) all-purpose flour
1 tablespoon ground cinnamon
1 teaspoon baking powder
½ teaspoon baking soda
½ teaspoon salt
½ cup (120g) buttermilk
1½ sticks (170g) unsalted butter
3 cups (340g) confectioners’ sugar
1 teaspoon pure vanilla extract
Pinch of ground cinnamon
Pinch of fine sea salt
¼ cup boiled cider (to make your own, see the footnote)
1. Preheat the oven to 350°F. Grease a 9-by-13-inch baking pan.
2. Make the Cinnamon Sheet Cake: In a large bowl, whisk the oil, sugar, brown sugar and melted butter until well combined.
3. Add the eggs one at a time and whisk well to combine before adding the next. Whisk in the vanilla.
4. In a medium bowl, whisk together the flour, cinnamon, baking powder, baking soda and salt.
5. Add the dry mixture to the wet mixture, stirring with a rubber spatula to combine. Mix in the buttermilk and scrape the bowl well to ensure it’s homogenous.
6. Pour the batter into the pan and spread it into an even layer. Bake until a toothpick inserted into the center comes out clean, 30 to 35 minutes. Remove from the oven and cool completely.
7. Make the Cider Frosting: In the bowl of an electric mixer fitted with the paddle attachment, cream the butter and confectioners’ sugar on medium speed until light and fluffy, about 4 minutes. Scrape the bowl well, then add the vanilla, cinnamon and salt; mix to combine.
8. With the mixer running on medium speed, add the boiled cider in a slow, steady stream. Mix until well incorporated.
9. Spread the frosting on top of the cooled cake. Serve immediately, or keep covered for up to a day at room temperature.
Note: You can make your own cider syrup by reducing 1½ cups apple cider to ½ cup, then whisking in 3 tablespoons sugar and continuing to cook, stirring occasionally, until the mixture is reduced to ¼ cup. Cool 10 minutes before using.