In an effort to wrest the ice-cream cake genre from the under-ten set, I offer this thoroughly grown-up rendition, a five-layer cake in which the three bands of chocolate ganache alternate with layers of raspberry ice cream.
The ice cream is a made in a food processor. If yours isn't big enough to accommodate a quart of ice cream, make the filling in two batches. Or you can mash berries and mix in softened ice cream with a spatula.
1 3/4 sticks (14 Tbsp.) unsalted butter, cut into pieces
9 ounces bittersweet chocolate, coarsely chopped (about 3 large bars)
1/2 cup sugar
8 large pasteurized eggs
1 (10-ounce) package frozen raspberries in syrup, thawed
1 Tbsp. Framboise (raspberry eau-de-vie), Chambord, or other raspberry liqueur (optional)
1 quart vanilla ice cream
1 pint fresh raspberries, for decoration (optional)
Whipped cream, for serving (optional)
Chocolate sauce, for serving (optional)
Active time: 1 hour
Total time: 10 hours
Note: The active work time on this torte is minimal, but the waiting around is considerable. You need to wait 30 to 45 minutes for each layer of the torte to freeze before you can top it with the next layer, so plan ahead.
Oil or lightly spray (with vegetable cooking oil) an 8 or 8-1/2- inch springform pan. Or you can use a disposable metal loaf pan and cut the finished cake out using scissors.
Put the butter and chocolate in a heatproof bowl, set the bowl over a saucepan of simmering water, and warm the ingredients, stirring occasionally, until melted. Be gentle with the heat—you don't want the butter and chocolate to separate. Transfer the bowl to the counter and whisk in the sugar. Slowly whisk in the eggs, one at a time.
Rap the bowl against the counter to get any bubbles out of the ganache, and pour 1/3 of it into the pan. Freeze for at least 60 minutes to set the ganache. Press a piece of plastic wrap against the surface of the remaining ganache and keep it on the counter.
When the first layer of ganache is set, start making the raspberry ice cream. Puree the raspberries in a food processor, or mash with a fork. Add the liqueur, if using, and stir to incorporate. Spoon the ice cream into the processor, if using, and pulse just until it is blended with the puree – don’t process so long that the ice cream melts. Or use a spatula to mix raspberries and ice cream together.
Spread 1/2 the ice cream over the ganache layer, return the pan to the freezer, and freeze for at least 30 minutes. Scrape the remaining ice cream into a bowl, cover with a piece of plastic wrap, and keep it frozen.
When the raspberry layer is set, pour half of the remaining ganache over it. Return the pan to the freezer for another 30 minutes. When it’s time to spread over the next layer of ice cream, beat the ice cream with a wooden spoon to slightly soften. Spread the last of the raspberry ice cream over the ganache layer and freeze for at least 30 minutes.
Finish by pouring the remaining ganache over the ice cream. Jiggle and tilt the pan, if necessary, to even the layer, then cover the top of the pan with plastic wrap (don’t let it touch the chocolate) and freeze the torte for at least 6 hours.
About 30 minutes, or up to 3 hours, before serving time, unmold the torte. Warm the sides of the pan slightly with warm water, then remove pan or cut away the edges. Pop the torte back into the freezer for 30 minutes, or more, so that the warmed sides can re-firm.
If you want to decorate the top of the torte with fresh berries, do this right before serving. To soften the ganache layer just enough to hold the berries, warm the top with a quick puff of air from a hairdryer, or run a long knife under hot water, wipe it dry, and pass it quickly over the top of the cake. Arrange the berries over the torte, put the torte on a platter, and head for the table. The torte can be served plain, with whipped cream, or with chocolate sauce.