Name: Apple Cider Doughnut Cake with Dulce de Leche Buttercream
Cook time: P0Y0M0DT1H15M0.000S
Total time: P0Y0M0DT3H0M0.000S
Yield: 10 to 12 servings
Ingredients: 3 cups apple cider; Nonstick cooking spray; 2 1/4 cups all-purpose flour (see Cook’s Note); 1 tablespoon apple pie spice; 2 teaspoons baking powder; 1/2 teaspoon baking soda; 1/2 teaspoon fine sea salt; 1 cup granulated sugar; 1/2 cup packed dark brown sugar; 4 tablespoons unsalted butter, melted; 1/2 cup neutral oil, such as vegetable or canola; 3 large eggs, at room temperature; 3/4 cup sour cream, at room temperature; 1 tablespoon pure vanilla extract or vanilla bean paste; 3 sticks (1 1/2 cups) unsalted butter, at room temperature; 3/4 cup confectioners’ sugar; 1 teaspoon pure vanilla extract or vanilla bean paste; 1/2 teaspoon fine sea salt; One 13.4-ounce can dulce de leche (see Cook’s Note); 1/2 cup granulated sugar; 1/2 teaspoon apple pie spice; 2 tablespoons unsalted butter

Directions

Special equipment:

a small offset spatula; a piping bag fitted with a large star tip

For the apple cider cake: Heat the apple cider in a large saucepan over medium-high heat until reduced to 3/4 cup, 20 to 30 minutes. Let the reduced cider cool to room temperature in a liquid measuring cup, about 30 minutes. (If the cider reduces too much, pour enough apple cider into it until it reaches 3/4 cup.)
Meanwhile, position a rack in the center of the oven and preheat to 350 degrees F. Spray two 8-inch round cake pans with cooking spray and line each pan with a parchment round. Set aside.
Whisk the flour, apple pie spice, baking powder, baking soda and salt together in a medium bowl until thoroughly combined. Set aside.
Beat the granulated sugar, brown sugar, melted butter and oil in the bowl of a stand mixer fitted with the paddle attachment on medium-high speed until combined, about 2 minutes.
Lower the speed to medium, add the eggs one at a time, beating until each egg is fully incorporated before adding the next. Beat in the sour cream and vanilla until smooth. On low speed, beat in half of the flour mixture just until combined. Beat in the reduced apple cider and then the remaining flour just until smooth. Scrape the bottom and sides of the bowl with a rubber spatula to incorporate any loose flour.
Divide the batter between the prepared cake pans and smooth the tops. Lightly rap the pans on the counter to remove any large air bubbles. Bake on the middle rack of the oven until a toothpick inserted in the centers comes out clean and the sides of the cakes pull away from the pans, about 40 minutes.
Remove the cakes from the oven and place on a cooling rack until the pans are cool enough to handle, about 20 minutes. Run a thin knife or offset spatula around the edges of a pan, flip the cake onto the cooling rack and remove the parchment paper. Repeat with the other cake. Let the cakes cool completely, about 40 minutes.
When the cakes are cooled, make the dulce de leche buttercream: Whip the butter in the bowl of a stand mixer fitted with the whisk attachment on high speed until light and fluffy, about 3 minutes, occasionally scraping down the bottom and sides of the bowl with a rubber spatula. Add the confectioners’ sugar, vanilla and salt and whip on medium speed to start, gradually increasing to high speed. Whip until light and fluffy, about 2 minutes. Reduce the speed to medium and whip in the dulce de leche in 3 additions. Increase the speed to high and whip until light and fluffy, about 2 minutes. Set aside.
For the spiced sugar coating: Stir the granulated sugar and apple pie spice together in a shallow bowl until combined. Microwave the butter in a microwave-safe bowl on high until melted, about 45 seconds. Working with one cake round at a time, use a pastry brush to brush the sides of the cake with the melted butter, then dip the sides of the cake into the spiced sugar so it looks like a sugared doughnut. Place the cake back onto the cooling rack. Repeat with the other cake layer. (See Cook’s Note.)
Place one sugared cake on a large serving platter or cake stand. Lay one hand gently on top of the cake to steady it, then use a serrated knife to gently saw through the side of the cake to create 2 thinner layers. Carefully transfer the cake back onto the cooling rack. Repeat the same steps with the second cake to create 4 layers in total. Leave the bottom layer on the platter.
Spread a heaping 1/2 cup dulce de leche buttercream to the edges of the layer on the platter with a small offset spatula. Place another layer of cake on top of the buttercream and spread with another heaping 1/2 cup buttercream. Repeat with the other 2 cake layers but leave the top layer unfrosted.
Transfer the remaining buttercream to a piping bag fitted with a large star tip. Pipe decorative stars along the edge of top cake layer to form a ring. Sprinkle about 1 tablespoon spiced sugar into the center and spread it to the buttercream stars so it looks like a sugared doughnut. You can slice and serve the cake immediately, but leaving it at room temperature for about 4 hours will soften it and make it more tender. Leftover cake can be covered or placed in an airtight container for up to 3 days. Just be sure to bring the cake back to room temperature, about 1 hour, before serving to soften the buttercream.

Cook’s Note

hen measuring flour, we spoon it into a dry measuring cup and level off excess. (Scooping directly from the bag compacts the flour, resulting in dry baked goods.) Canned dulce de leche is consistently thick, making it the best choice for this buttercream recipe. You can also pick up a cake layer and place it on one hand and coat the sides with sugar with the other hand.