Pumpkin Mousse Cake

By cwyorkiex3

To make fresh pumpkin puree, choose a firm-fleshed cooking pumpkin. (Avoid large field pumpkins used for jack-o'-lanterns as they are too watery.) Cut in half through the stem end and place, cut sides down, on a baking pan lined with parchment paper. Bake in a preheated 350°F oven until a skewer pierces the flesh, about 25 minutes. Scoop out the seeds, scrape the flesh from the skin and puree in a food processor. The puree should be the consistency of canned pumpkin. If it is too thin, cook over low heat until thickened. Freeze leftover puree for up to 3 months.

The génoise, a light, elegant sponge cake, is one of the building blocks of French baking, used as a base for both jelly rolls and layer cakes, such as our Pumpkin Mousse Cake (see related recipe at right). The successful leavening of the cake depends solely on how much air is whipped into the eggs. Heating the sugar and whole eggs before whipping helps the eggs attain the maximum volume possible, although a slightly denser, still satisfying, version of the cake can be made without this step. Some génoises, such as this recipe, contain a little butter, which tenderizes the crumb.

Ingredients

• For Génoise (Cake):
• 4 eggs
• 1 ⁄2 cup sugar
• 3 ⁄4 cup cake flour, sifted
• 3 Tbs. unsalted butter, melted
• For Mousse:
• Génoise
• 2 1/4 tsp. (1 envelope) unflavored gelatin
• 2 Tbs. cold water
• 1 3/4 cups fresh pumpkin puree or
• canned pumpkin puree
• 1/2 cup granulated sugar
• 1/4 tsp. salt
• 1/4 tsp. ground cinnamon
• 1/4 tsp. ground cloves
• 1/4 tsp. freshly grated nutmeg
• 1 Tbs. dark rum
• 1 2/3 cups plus 1/2 cup heavy cream
• 1 tsp. confectioners’ sugar

Details

Adapted from williams-sonoma.com

Preparation

Step 1

For Génoise (Cake):
Preheat an oven to 375°F. Line the bottom of a 9-by-3-inch round cake pan with parchment paper.

In the bowl of a stand mixer, whisk together the eggs and sugar by hand until combined. Place the bowl over but not touching simmering water in a saucepan and gently whisk until the mixture registers 140°F on an instant-read thermometer, about 3 minutes. Put the bowl on the mixer fitted with the whisk attachment and beat on high speed until the mixture is pale and almost tripled in volume, 5 to 8 minutes.

Remove the bowl from the mixer. Sift the flour over the egg mixture in two additions and carefully fold in with a large rubber spatula. Fold a large dollop into the melted butter, then fold back into the egg mixture.

Pour the batter into the prepared pan and smooth the top. Bake until the top is browned, about 20 minutes. Transfer the pan to a wire rack and let cool completely. Run a table knife around the edge of the pan and invert the cake onto a work surface. Turn the cake right side up. Use as directed in the specific recipe for a layer cake or jelly roll.
Makes one 9-by-3-inch cake.

For Mousse:
Make the génoise as directed, let cool completely and place the cake, right side up, on a work surface. Cut the cake into 2 equal layers.

In a small bowl, sprinkle the gelatin over the cold water, stir and let soften until opaque, about 3 minutes.

In a saucepan over medium heat, combine about 1/2 cup of the pumpkin puree, the granulated sugar and salt and heat, stirring, until the sugar dissolves. Stir in the softened gelatin and let cool to room temperature. In a bowl, stir the pumpkin mixture into the remaining pumpkin puree. Whisk in the cinnamon, cloves, nutmeg and rum.

Using a stand mixer or by hand, whip the 1 2/3 cups cream to soft peaks. Using a large rubber spatula, gently fold one-third of the whipped cream into the puree, then fold in the remaining cream, making a mousse.

Peel off the paper from the bottom cake layer. Put the layer, cut side up, into the bottom of a 9-inch round springform pan. Spread half of the mousse evenly over the cake. Trim 1/2 inch from the outside edge of the remaining layer. Center it, cut side down, on top of the mousse. Top with the remaining mousse, pushing it between the cake and the pan and smoothing the top. Refrigerate until set, at least 4 hours or up to overnight.

Warm the sides of the pan with a kitchen towel soaked in hot water and wrung out. Remove the pan sides and smooth the sides of the mousse with a frosting spatula.

Whip the 1/2 cup cream and the confectioners' sugar to medium peaks. Spoon into a pastry bag fitted with a 1/2-inch star tip (see related tip at left). Pipe shells around the top edge and a few in the center of the cake. Run a thin knife under the cake to free it from the bottom of the springform pan and transfer to a serving plate. Refrigerate until ready to serve. Serves 10 to 12.