Praline celebrates Halloween with specialty desserts, including these chocolate spider cakes.

The display cases at Praline Bakery & Bistro are packed with sugary delights: eclairs, apple tarts, hazelnut layer cakes, macarons. And, around this time of year, eight-legged arachnids — of the chocolate variety. Praline’s “Halloween spider cakes,” sour cream chocolate pound cakes layered with ganache and finished with hand-piped hard chocolate legs and eyes, are seasonal stars of the French bakery. Created by co-owners and former White House chefs Susan Limb and Patrick Musel and sold at the shop since 2007, the desserts — available in large ($40; feeds 8 to 10) and individual ($4.75) sizes — are equal parts whimsy and creepy. “We wanted to do something fun and different” for Halloween, Limb says, “the kind of stuff you don’t see around town.” Despite the treats’ kid-friendly appeal, they’re no cakewalk to make; Limb says each is the product of a two-day process, including the laborious step of hand-piping eight chocolate legs per spider. With typical sales of 40 to 50 large cakes and 250 to 300 minis, that’s a whole lotta legwork.

The Legs

It takes a steady hand to pipe chocolate onto parchment paper in the proper “slanty seven” shape of spider legs, Limb says. If you don’t pipe fast enough, “the chocolate will puddle or get kind of squiggly.” Too slow, and the chocolate will harden inside the piping bag. In addition, the temperature in the bakery’s special chocolate room needs to be just right (between 68 to 70 degrees Fahrenheit). At the ideal temperature, the chocolate hardens, or “sets,” in five minutes.

The Body

The body of the large spider cake is baked inside a round dome mold, then sliced into three layers. Bakers fill each layer with a chocolate cream ganache. They also coat the inside of the empty mold with ganache, and then “rebuild it upside down in the mold,” Limb says. After the cake and ganache sit inside the mold for a few hours, the frosted dessert is released and dusted with Dutch cocoa powder. The head is made the same way as the body, but with only two layers of cake.

The Eyes

The eyes (both white and dark chocolate) are hand-piped. As with the legs, the chocolate has been “tempered,” meaning that the chocolate has a glossy, smooth texture that stays hard at room temperature. Tempering involves heating and cooling chocolate so that it forms a specific sort of crystal structure (without this process, melted chocolate resolidifies in a less pretty and less tasty way, often with white streaks).

Praline Bakery & Bistro, 4611 Sangamore Road, Bethesda; 301-229-8180.