Today, these ice cream and cake sandwiches rely on chocolate—not sugar—for richness and flavor.
People often ask me how I'm able to work at Flour and not eat everything in sight. "I would never stop eating!" they tell me. When you're surrounded by pastries all day, after a while you really do become somewhat immune to all of the temptation.
There is one pastry we make that I can never pass up: our triple chocolate mousse cake. It consists of layers of milk, white, and dark chocolate mousse in between thin sheets of chocolate cake. (See why it's hard to resist?) Once it's assembled, we freeze the whole thing, trim it, and cut it into various sizes. The trimmings taste like the best ice cream cake ever. I simply can't walk by them without snacking. The rich mousses become like ice cream when frozen—creamy and soft and chocolaty.
I wanted to see if I could replicate this cake without using any white sugar. What would happen if we took this cake, made it a single layer, and cut it into rectangles? Ice cream sandwiches—that's what!
The mousse is actually a whipping ganache—chocolate and heavy cream mixed together and then whipped up soft and fluffy. The sugar that is in the chocolate is enough to sweeten the mousse. I use a bittersweet chocolate (which does have a small amount of sugar in it) and then I infuse the mousse with some mint to make a chocolate-mint flavor. The cake itself is also sweetened only by the chocolate, and the result is a super chocolaty cake that works great as the “bread” for the ice cream sandwich.
The challenge of making any frozen treat without sugar is that sugar actually depresses the freezing point of liquids. Take water, which freezes solid into ice at 32° F. If you mix sugar into it, it will freeze at a much lower temperature; with enough sugar, it will be soft and slushy and you can run a spoon through it. Pastry chefs use this property of sugar to great advantage by adding sugar to fruit purées to make sorbets and to custards to make ice creams. If you omit sugar, like I do in these mint-chocolate ice cream sandwiches, then you run the risk of rock-hard treats.
More: Alice Medrich shares 3 tips for chocolate ganache.
I address that in a few ways here. First, there is sugar in the mousse—just not added sugar. The sugar that is in the chocolate itself helps keep the mousse from freezing rock-hard. Second, to compensate for how firm the sandwiches get, you really do have to remove these from the freezer at least 15 minutes before serving. As the sandwiches start to defrost, they become softer and ready to eat.
One of the things I love most about baking with less sugar is that you end up highlighting all of the other flavors so much more when you don't have sugar to focus on—and that's exactly what happens here. These are deeply chocolaty and minty and well worth the 15-minute wait.
Makes 8 sandwiches
For the ice cream:
480 grams (2 cups) heavy cream
20 grams (1/2 cup packed) fresh spearmint or peppermint leaves, coarsely chopped, or 1 teaspoon peppermint extract
85 grams (3 ounces) bittersweet chocolate, finely chopped
1/4 teaspoon kosher salt
For the cake:
225 grams (8 ounces) bittersweet chocolate, chopped
5 large eggs, separated
60 grams (1/4 cup) strong brewed coffee, at room temperature
1/4 teaspoon kosher salt
35 grams (1/4 cup) all-purpose flour
First photo by Joseph De Leo; other photos by James Ransom