Orange Cake with Grand Marnier Sauce

° Serves 6

I use a prepared sponge cake from the supermarket for this recipe, but you can bake your own. The Suzette butter, which I also use in the Gratin of Crepes Suzette, makes an easy and flavorful buttercream. The cake is served with a Grand Marnier sauce and garnished with thin slices of orange. I don’t use much sugar in the Suzette butter or in the sauce, because commercial cakes are quite sweet.

• 1 round sponge cake (8 ounces), about 7 inches in diameter and 1½ inches thick
• Suzette Butter
• 4 tablespoons (½ stick) unsalted butter, softened
• 1½ teaspoons grated orange rind
• 2 tablespoons orange juice
• 1 tablespoon confectioners’ sugar
• 3 tablespoons orange juice
• Sauce
• 1 cup sour cream
• 1 tablespoon Grand Marnier
• 1 tablespoon confectioners’ sugar
• Garnish
• 1 large seedless orange

Split the cake horizontally into 2 layers. Place one layer on a serving plate.

Prepare the Suzette butter: Place the butter in a food processor and add the orange rind, orange juice, and confectioners’ sugar. Process until combined. (At first the mixture may not blend; keep processing until the butter absorbs the juice.)

Spread the Suzette butter over the top of the first cake layer and place the other cake layer on top. Sprinkle it with the 3 tablespoons orange juice. (At this point, the cake can be wrapped in plastic wrap and stored in the refrigerator for up to 24 hours.)

Prepare the sauce: Mix the sour cream, Grand Marnier, and confectioners’ sugar in a small bowl. Set aside.

Completely remove the skin from the orange, including the cottony white pith underneath, and cut the orange into slices.

At serving time, cut the cake into 12 thin wedges. Place a spoonful of sauce on each dessert plate, arrange 2 small wedges of cake on the sauce, and top with an orange slice. Serve immediately.

You can prepare the cake ahead of time and then make the sauce in just a few minutes before serving.