Ask Martha: Chocolate ganache

Think of it as the gift that keeps on giving. Start with one easy and irresistible chocolate recipe and adapt it for all kinds of uses.

Chop. Pour. Stir. Nothing up your sleeve, no sleight of hand. Those three basic steps are all there is to making an irresistible batch of ganache. Despite its French name, ganache is nothing elaborate, just chopped chocolate melted in heated heavy cream, with just a bit of salt to bring out the flavor.

Your first impulse will be to sit down and eat this luscious concoction with a spoon. But if you can restrain yourself, that's when the real magic happens, because ganache can be used in a multitude of ways.

While it's still warm, ganache can be poured directly from the bowl over a cake for a can't-fail glaze. Or piped into tartlets. Or it can be whipped into a fluffy frosting or whoopie-pie filling. Mixed with peanut butter, chilled and rolled, it turns into truffles.

Ganache

This recipe (which can easily be multiplied) is the base for all the variations that follow.

It makes 1½ cups.

Coarsely chop 8 ounces of semisweet or bittersweet chocolate (we like 61 percent cacao). A serrated knife is best for the job.

Bring 1 cup heavy cream just to a boil over medium-high heat. Pour over chocolate, and add 1/8 teaspoon coarse salt. Let stand for 10 minutes (don't stir; it will cool the ganache too quickly, making it grainy).

Stir with a whisk until smooth and shiny to break up pieces and emulsify the cream and chocolate.

Scrape the dish with a spatula to incorporate all of the chocolate, which often settles in the bowl.

Cooking tip: If the fat starts to separate from the cream, much like the oil in a vinaigrette, fret not. To bring a "broken" ganache back, whisk in water, 1 tablespoon at a time, until the mixture is smooth and emulsified. Resist the impulse to add cream, which will disrupt the ratio of chocolate to fat: generally, 1 ounce chopped chocolate for every fluid ounce of heavy cream (plus 1/8 teaspoon coarse salt for every 8 ounces of chocolate).

Glaze or filling

While ganache is still hot and fluid, it makes a show-stopping pour-on cake glaze or a glossy filling for tartlets.

Before pouring the ganache, set cake on a wire rack over a baking sheet. The excess will pool in the tray and you'll be able to cleanly lift the cake away (and equally important, reuse any leftovers).

For more precise applications, such as filling tartlets, use a disposable pastry bag with a small opening, which will provide control as you pipe the liquid.

Frosting

When beaten at room temperature, ganache fluffs up like whipped cream (which, given its heavy-cream content, makes perfect sense). For a smoother and denser frosting, whip the ganache less; for a fluffier, lighter one, whip it longer.

Let ganache cool to room temperature, stirring often, 45 minutes to 1 hour. Beat it with a mixer on medium-high speed, until paler and fluffy, two to four minutes. (This will yield about 2 cups.) Transfer to a disposable pastry bag with a large opening and use it as a filling for mini whoopie pies. Alternatively, spread it over cupcakes.

Truffles

Refrigerated and firmed up, ganache has the perfect texture for rolling into truffles. We flavored our batch with peanut butter. Adding liqueur or a flavored extract is another option, as is rolling chilled ganache straight-up.

• Peanut butter truffles: Immediately after making the ganache, add it little by little to 1 cup smooth peanut butter, whisking constantly, until smooth. Refrigerate in a 5-inch by 8½-inch glass loaf pan, covered, until firm, four hours to overnight. Scoop with a 1¼ -inch ice cream scoop and roll into smooth balls with your palms. (If mixture softens, refrigerate until firm.) You will have about 28 truffles. Roll each in unsweetened Dutch-process cocoa powder, tapping gently to remove excess. Refrigerate in mini baking cups for up to four days).