Instant Orange Cake

"I made this dessert one evening when friends came by for drinks and didn’t leave. I found a pound cake in the freezer and a couple of oranges and some leftover mascarpone in the refrigerator, although crème fraîche or sour cream would have done as well. Often these impromptu dishes work out the best." --Jacques Pépin

Recipe: Instant Orange Cake

Serves 4

Ingredients:

3 seedless oranges (about 10 ounces each)
1/2 cup mascarpone cheese
1 tablespoon sugar
1 pound cake (12 ounces), brown edges trimmed off all around, cut lengthwise into 3/4-inch slices
2 tablespoons Grand Marnier
1/2 cup orange marmalade
A few fresh mint sprigs, for decoration

Instructions:

Using a sharp knife, peel the oranges, removing the skin and pith so the flesh is exposed. Cut between the membranes of the orange and remove the segments (you will have about 25). Then squeeze the membranes over a small bowl to extract all the juice (about 1/3 cup) and reserve it.
Mix the mascarpone cheese with the sugar.
Arrange the slices of pound cake side by side in the bottom of a gratin dish, pie plate, or glass platter (about 9 inches across and 1 inch deep) nice enough to go to the dining room.
Mix half the reserved orange juice with the Grand Marnier and sprinkle it on the cake slices. Spread the mascarpone on top and arrange the orange segments on top of the mascarpone.
Combine the remaining juice with the orange marmalade and coat the orange segments with it. Decorate with the mint.
Serve, using a large spoon to lift up the cake.